HDL v Waseem Butt & Anor [2025] EWHC 3410 (KB)

[2025] EWHC 3410 (KB)Case No KB-2025-003174
IN THE HIGH COURT OF JUSTICE
KING'S BENCH DIVISION
Venue Royal Courts of Justice, Strand, London, WC2A 2LLDate 31/12/2025
Before
CLARE PADLEY(SITTING AS A DEPUTY HIGH COURT JUDGE)
Between
HDL (by his Litigation Friend, RCK)Claimant(2) RSA INSURANCE LTDDefendants
Nathan Tavares KC (instructed by Enable Law) for ClaimantMarc Willems KC (instructed by DWF Law LLP) for DefendantsHearing Hearing dates: 11 December 2025
APPROVED JUDGMENT

Clare Padley (sitting as a Deputy High Court Judge) :

[1]This claim for damages for personal injury arises out of a road traffic accident which took place on 10 April 2021. The Claimant, who was born in January 2020, was 15 months old at that time. He was travelling with his mother in a car driven by the First Defendant, his mother’s partner. He is now 5 years old. This claim has been brought on his behalf by his mother as his litigation friend. An anonymity order has already been made in this case which remains in place.[2]This judgment follows a recent hearing on 11 December 2025. There were two applications listed before the court on that date: i) the Claimant’s application for an interim payment dated 29 September 2025; ii) the Claimant’s application for summary judgment dated 24 November 2025.[3]Mr Nathan Tavares KC appeared for the Claimant and Mr Marc Willems KC appeared for the Defendants and I am grateful to them both for their skeleton arguments and oral submissions.[4]At the start of the hearing, Mr Willems confirmed that the Defendants were no longer resisting the Claimant’s application for summary judgment and accepted that judgment could be entered for the Claimant with damages to be assessed. I then directed that judgment would be entered by consent with damages to be assessed.[5]The remainder of the hearing was concerned with the Claimant’s application for a further interim payment.

Factual background

[6]The accident happened on the M5 motorway at about 7.00 pm in very wet weather. The First Defendant lost control of the vehicle, causing it to descend down an embankment where it rolled and came to a rest on its roof.[7]As a result of the accident the First Defendant was convicted of driving without due care and attention by Worcestershire Magistrates on 20 October 2021. His licence was endorsed with nine points, and he was given a fine.[8]The Claimant’s initial injuries were summarised in the case summary prepared by his solicitors for this hearing as follows:
“The Claimant suffered a serious traumatic brain injury in the accident, which is classified as severe according to the Mayo Clinic criteria. CT imaging following the accident showed evidence of parenchymal haemorrhage, a right-sided subdural haematoma, a coup contrecoup injury and left-sides midline shift. This was a very severe traumatic brain injury with haemorrhage in all compartments of the brain. The following day, the Claimant underwent a right-sided craniotomy and evacuation of the haematomas, and a skull fracture was noted during the surgery. The Claimant subsequently developed chronic infection in his craniotomy bone flap and on 19 September 2021 the bone flap was removed. Thereafter he had to wear a helmet to protect the vulnerable part of the skull until a titanium plate was inserted on 27 July 2023.”
[9]This summary is consistent with the expert medical evidence served by the Claimant with his claim and the Defendants have accepted in the defence that the Claimant sustained a severe traumatic brain injury in the accident.[10]The Claimant’s case is that this traumatic brain injury resulted in regression in the Claimant's development and that he has been left with significant cognitive, motor and speech impairments as a result of it. The Claimant’s medical evidence also indicates that he has significant behavioural concerns and traits similar to autism spectrum disorder (ASD). In summary, the Claimant’s case is that he needs constant 1:1 care, special accommodation, and a multidisciplinary team of therapists, as outlined in detail in the report of Dr Ruth Kent, Consultant in Rehabilitation Medicine, dated November 2025 and the case management update report.[11]I will return to the Defendants’ position in more detail in due course, but in short, causation of the Claimant’s current and ongoing symptoms is not admitted by the Defendants and was expressly put in issue in their defence.

Procedural chronology

[12]This claim was sealed and issued for service on 21 August 2025, and an anonymity order was made by Master Eastman on 28 August 2025. The claim was served on 10 September 2025, and the defence was filed and served on 5 November 2025.[13]In the defence, although the broad factual circumstances of the accident, the First Defendant’s conviction, and the Second Defendant’s motor insurance policy were admitted, there was no formal admission of liability.[14]The Defendants also did not admit that all the Claimant’s current symptomology can be attributed to the injuries sustained in the relevant accident and put causation and quantum in issue. In particular, the defence refers to the fact that the Claimant has been identified by genetic testing as having a chromosomal abnormality, namely a duplication of the 22q11.2 gene (described erroneously in some of the medical reports and in the original defence as a deletion or DiGeorge Syndrome) and that the Claimant’s health records indicate some developmental concerns prior to the accident.[15]It was against this background, and an earlier without prejudice admission of liability in pre-action correspondence, that the application for summary judgment was made, which has now been agreed to by the Defendants.

Material for this hearing

[16]For the hearing on 11 December 2025, the court was initially provided with a hearing bundle including anonymised pleadings, the two applications and supporting evidence from the Claimant including medical expert reports from Dr Kent and Professor Conor Malluci, Consultant Paediatric Neurosurgeon dated November 2025, an updated schedule of loss and a case management report.[17]The Claimant’s solicitors then filed a supplementary bundle on 9 December, including some police records and some health records, which was then superseded by their further witness evidence.[18]In response to the applications, a witness statement was filed by the Defendants’ solicitor, Sarah Catherine Mir (which is erroneously dated 8 October 2025 but was signed on 8 December 2025) together with an addendum bundle including a short genetics expert report dated 8 December 2025 from Dr Reardon, a Consultant Clinical Geneticist, and a draft amended defence and counter-schedule. No application to amend the pleadings has yet been made, so there will have to be a proper application in due course in relation to that.[19]The Claimant’s solicitor, Ms Stoll then served an additional witness statement in reply on 10 December 2025 together with a medical genetics expert report from Professor Peter Scambler, Emeritus Professor of Molecular Medicine, dated 5 December 2025.[20]As I noted to the parties during the hearing, it was very unfortunate that the evidence filed by both sides in relation to this interim payment application did not follow the procedure provided for in CPR 25.21. However, as both parties wished to proceed with the hearing, and given the stated urgency of the Claimant’s application, I indicated that having regard to the overriding objective, I would allow both parties to rely on all the evidence that had been filed and to proceed with the application for an interim payment.[21]Finally, following the hearing, I was sent by email from Mr Tavares a copy of the referral for genetic testing by the treating paediatrician, Dr Sharples, in June 2021, which had been referred to by both genetic experts. Mr Tavares also sent in a further written note relating to the court’s general discretion in relation to interim orders and made reference to some sections of the White Book.

Interim payment application

[22]The Claimant is seeking a further interim payment in the sum of £225,000 pursuant to CPR 25.1(1)(l). I note that the Second Defendant has already made voluntary interim payments totalling £980,000 between August 2021 and August 2025 and funded some initial treatment and therapy under the Rehabilitation Code.[23]In the appendix to the application, the Claimant’s solicitor Ms Stoll set out the details of Claimant’s traumatic brain injury and his initial surgery and treatment and his current symptoms which include significant behavioural symptoms.She stated at paragraph 10:
“Prior to the accident the Claimant had been developing normally.”
She then referred to the genetic chromosomal abnormality referred to in the defence and stated:
“The Claimant did not present with signs of any of these complications and his current presentation is overwhelmingly due to the severe traumatic brain injury suffered in the index accident.”
No reference was made in her statement to the entries in the Claimant’s pre-action medical records set out in the defence which are alleged by the Defendants to refer to pre-accident concerns about his development.[24]Ms Stoll stated in the application that the interim payments received to date have been used: i) to fund support from a specialist brain injury case manager from Westcountry Case Management and for care and rehabilitation, including agency carers who provide the Claimant with one-to-one care at all times when he is not in school, where he also receives additional support; ii) to fund a team of treating therapists who provide ongoing rehabilitation to the Claimant, namely a physiotherapist, occupational therapist and speech and language therapist. They have also provided input to the Claimant's care team; iii) to assist with accommodation costs as larger accommodation was required to accommodate the Claimant, who needs rooms on the ground floor, so he does not need to use stairs in light of his left-sided weakness and to also provide therapy space for him at home; iv) to assist with transport costs, including the purchase of a specialist vehicle that can transport the Claimant in his wheelchair, aids and equipment; v) to fund the input required from a professional deputy as the Claimant lacks capacity.[25]Ms Stoll stated that a further interim payment of £225,000 has been requested to ensure there are sufficient funds going forward to provide the same level of care and rehabilitation that the Claimant requires as a result of the serious brain injury he suffered in the accident and to ensure there is no disruption to the care and rehabilitation support required by the Claimant. She believes “this request is entirely reasonable and proportionate on a claim in which the Claimant suffered a serious brain injury for which liability is admitted and on a claim which will be worth in excess of £10 million pounds.”[26]In her witness statement dated 27 November 2025, Ms Stoll then stated that the likely value of the claim is put at £15 million. During the hearing, Mr Tavares told the court that he estimated the likely value of the claim to be at least £20 million based on an ongoing need for 1:1 care and a higher figure if 2:1 care was needed in the future.[27]In her witness statement, Ms Stoll asserts that the Claimant’s claim for general damages, estimated on a conservative basis, plus his past losses to date and his care, case management, therapy and miscellaneous costs for the next 6 months total £1,569,958.60.[28]The Claimant and his family have moved a number of times since the accident and are now living in a 6 bed-roomed house in Winterbourne. Rent for this property is paid a year in advance, and £44, 100 has been paid for the annual rent up to 21 April 2026. If next year's rent payment, which is due on 22 April 2026, is added, Ms Stoll asserts that the total value of general and special damages to that date would be £1,615,800.50.[29]She then estimates that if care and case management and therapy costs for the next 12 months are included, then estimated on a conservative basis, this totals £1,783,792.90.[30]The further interim payment sought of £225,000 would bring the total interim payments to £1,205,000.[31]In support of the application, the Claimant initially relied on an updated case management report, an updated schedule of loss, and a medical report dated November 2025 from Dr Ruth Kent, Consultant in Neurological Rehabilitation.[32]In her report, Dr Kent reviewed the clinical history and provided an update of the Claimant’s current symptoms. She also addressed the issue of his genetic abnormality and cast doubt on the suggestion that there were any significant pre-accident developmental issues. Her conclusion was that:
“In the absence of major congenital abnormalities detected at birth or in the first year of life, my understanding is that whilst this chromosomal variant may or may not have contributed to any potential pre-injury language delay, the traumatic brain injury has undoubtedly created neurodevelopmental challenges far beyond what might have been expected from any premorbid genetic factor alone. Any interaction between preexisting vulnerability and acquired injury exemplifies the multifactorial nature of neurodevelopmental outcomes following early brain injury.”
[33]Dr Kent also summarised the Claimant’s current and likely future care needs, stating that “He will need lifelong 24-hour support, seven days per week, which will be the blueprint of a package that must adapt and intensify as he transitions through childhood into adulthood.” She then outlined in detail all his ongoing therapeutic needs. Her expert assessment of the Claimant’s needs forms the basis for the projected likely overall value of the claim as being in the region of £15-20 million.[34]The Claimant also relied on the medical evidence filed with the claim, from Mr Tonks, Consultant Paediatric Clinical Neuropsychologist, dated 16 October 2023.[35]The Claimant initially served no expert genetic evidence in support of the interim payment application.

Defendants’ evidence in response

[36]In her witness statement in response to the application, dated 8 December 2025, the Defendants’ solicitor Ms Mir, confirmed that causation of the Claimant’s ongoing symptoms remains firmly in dispute.She states that, despite that, “the Second Defendant has done the best they can and released £980k in interim payments.”[37]She confirmed that in light of their concerns about causation, which I note had been set out in correspondence to the Claimant’s solicitors since late November 2024, the Second Defendant had instructed a genetics expert, Dr Reardon, who had recently assessed the Claimant at home. Ms Mir stated that although his full report was not yet available, Dr Reardon had provided a short interim report in a letter dated 8 December 2025 which was exhibited to Ms Mir’s statement. In her statement Ms Mir summarised it by saying that it stated that: i) the Claimant's development pre-accident was delayed and/or atypical; ii) on balance that was caused by the duplication of the 22q11.2 gene; iii) but for the accident, the Claimant would have had needs which are similar to or identical to those which he presents with currently which, the Claimant avers, are attributed to the injuries sustained in the accident.[38]It is apparent from his report, that Dr Reardon travelled from Ireland to visit the Claimant’s home in late October 2025 and was able to examine the Claimant and talk to one of his carers. However, he states that he was refused permission to interview the Claimant’s mother or take a family history as he had intended. In his short report, he sought to correct the report of Dr Kent in terms of the wide range of possible outcomes of this chromosomal duplication and set out his clinical experience of patients with this genetic abnormality. His report is not a full one and it is not clear if he has seen all the material made available to the Claimant’s experts. It is supported by a declaration and statement of truth in accordance with CPR Part 35.[39]In short, the Defendants’ position is that in light of Mr Reardon’s expert evidence the Defendants are not prepared to voluntarily make any further interim payments, as they are concerned about the overall value of the claim. They contend that there is a significant risk of overpayment if their causation evidence is accepted and that as, in accordance with the case law, any risk of overpayment must be avoided, it is not appropriate to make a further interim order.[40]The Defendants also suggested that an urgent preliminary issue trial in terms of medical causation is critical in this case.[41]In addition to the critical causation issue, Ms Mir’s witness statement in response to the interim payment application makes reference to the Defendants’ ongoing significant concerns about the overall level of expenditure in relation to care and housing costs in this case, which they contend do not appear to be clinically mandated, reasonable nor proportionate. In particular, the Defendants are concerned that the Claimant’s mother has moved with the Claimant a number of times, with increasing costs involved, and has not always followed the advice of the professionals involved in the Claimant’s care. That said, Mr Willems confirmed during the hearing that the Defendants’ primary argument against the payment of any further interim payments at this stage is based on the live causation issue.

Claimant’s further evidence in response

[42]In response to the Defendants’ expert genetic evidence, the Claimant’s solicitor Ms Stoll then filed a further witness statement dated 10 December 2025. This exhibited some pre-accident medical records and an expert genetic report from Professor Peter Scambler dated 5 December 2025.[43]His report is described as a ‘preliminary’ expert report, but it appears to be a full report. In his report he states that the Claimant’s genetic testing has revealed an instance of a duplication within one of the two chromosomes 22. He confirms, which is now common ground between the parties, that it is not a chromosomal deletion and has been erroneously described as DiGeorge syndrome. He does not refer to the date of the genetic testing (which appears from the papers I have seen to have taken place sometime in June 2021 but the results of which were not reported to the Claimant until sometime in 2024), but he refers to some uncertainty about the reason, saying:
“It is unclear from the notes precisely what prompted the request for genetic testing. Mother’s concerns of possible delay in walking unsupported by clinical assessment would not normally be sufficient indication.”
[44]He then records various research studies into this chromosomal duplication and highlights the limitation of some of the data, including the impact of ‘ascertainment bias’, in other words, that all the medical literature will have some degree of bias towards the more severely affected cases. He concludes, based on his assessment of the limited pre-accident health records and other evidence available to him that:
“In the absence of injury I would have expected HDL to have had normal schooling, to be gainfully employed in adulthood and to live without care provision (see Biobank study). Overall, given the undoubtedly severe injury sustained by HDL, his pre-injury progress, and post-injury deficits compared to what we know about 22q11.2 duplication syndrome the balance of probability indicates to me that the great majority of the ongoing problems are a direct consequence of traumatic brain injury.”
[45]Professor Scambler is not a clinician, and he has not examined the Claimant. His report is also supported by a declaration and statement of truth in accordance with CPR Part 35.[46]Although Professor Scambler’s report was completed a few days before Dr Reardon’s, due to the later filing of this further medical evidence by the Claimant, neither genetic expert has had any opportunity to respond to the other’s report.

Test for interim payment

[47]The court’s powers to order an interim payment is a discretionary power, but it is not an unfettered discretion, and the power must be exercised in accordance with the conditions set down in the Civil Procedures Rules and the relevant case law.[48]The maximum amount which it is open to the court to order by way of an interim payment is set out in CPR 25 Part V. CPR 25.20 states:
“(1) The court must not order an interim payment of more than a reasonable proportion of the likely amount of the final judgment.”
[49]The evidential requirements and conditions for an interim payment are then set out in CPR 25.22 and 25.23.[50]Having ordered that judgment should be entered for the Claimant with damages to be assessed, I am satisfied that the condition in 25.23 (b) is met:
“(b) the claimant has obtained judgment against that defendant for damages to be assessed, or for another sum of money (other than costs) to be assessed.”
[51]The key issues in relation to this application for an interim payment are therefore: i) The likely amount of the final judgment; ii) Whether the amounts sought (in total) are more than a reasonable proportion of that amount.[52]In the Court of Appeal case of Eeles v Cobham Hire Services Ltd [2009] EWCA Civ 204 the court confirmed that in personal injury cases where a periodical payments order is likely to be made, the notional capitalised value of that order is excluded, and the interim payment can only be a reasonable proportion of the capital sum expected to be awarded on final judgment. The Claimant accepts the likelihood of a periodical payments order being ordered in this case and contends that the figures put forward by Ms Stoll are in accordance with the approach advocated in the first stage in Eeles.[53]The Court of Appeal in Eeles also gave some general guidance on the approach to such applications in paragraphs 43-44 of the judgment of LJ Smith:
“43. The judge's first task is to assess the likely amount of the final judgment, leaving out of account the heads of future loss which the trial judge might wish to deal with by PPO. Strictly speaking, the assessment should comprise only special damages to date and damages for pain, suffering and loss of amenity, with interest on both. However, we consider that the practice of awarding accommodation costs (including future running costs) as a lump sum is sufficiently well established that it will usually be appropriate to include accommodation costs in the expected capital award. The assessment should be carried out on a conservative basis. Save in the circumstances discussed below, the interim payment will be a reasonable proportion of that assessment. A reasonable proportion may well be a high proportion, provided that the assessment has been conservative. The objective is not to keep the claimant out of his money but to avoid any risk of over-payment.”
[44]For this part of the process, the judge need have no regard as to what the claimant intends to do with the money. If he is of full age and capacity, he may spend it as he will; if not, expenditure will be controlled by the Court of Protection.”[54]I have also had regard to all the factors set out in Popplewell J’s summary of the principles to be applied in paragraph 19 of his judgment in the case of Smith v Bailey [2014] EWHC 2569 (QB) in which the approach in Eeles was applied in another case concerning the purchase of accommodation.[55]It is plain from these cases that a judge should not at the interim payment stage embark upon a mini-trial or seek to determine issues which are properly to be left to the trial judge. It is also plain that a key principle for the court to consider is that the amount payable as an interim award should not be such as to expose the defendant to the risk that the eventual damages will be less than the sum or sums paid out as interim awards. I consider that this principle is particularly important in a case of this nature where there is no real prospect of any overpayment being repaid.[56]I was also referred by the parties to two High Court cases in which the approach to be taken to interim payments in a case where causation is in dispute were considered. Although it was acknowledged that they would not be binding on this court, it was submitted that they may be persuasive. The Claimant relied on the case of Sellar-Elliot v Howling [2016] EWHC 443 and the Defendants relied on the case of Farrington v Menzies-Haines [2019] EWHC 1297.[57]The Sellar-Elliot case was a decision by Sweeney J on an application for permission to appeal from a decision by Master Cook to order an interim payment in a clinical negligence case. In that case, the defendant had put medical causation in issue in the defence, but had chosen not to file any substantive expert causation evidence at the interim payment hearing in response to the claimant’s expert evidence report on causation which was filed a month earlier. Sweeney J refused permission to appeal and concluded: “48. Equally, it seemed clear to me that Master Cook was right to conclude that he had to decide the application on the evidence before him. It was also clear that, on that evidence, he was entitled to conclude that, absent any evidence of reasons to the contrary, the evidence of Professor Middleton was compelling, and thus to conclude, as he did, that the Claimant had proved, to the requisite standard, that the conditions in CPR 25.7(1)(c)were met.[49]To the extent that Master Cook relied on the decision in Smith (above) to conclude that he had to decide the application upon the evidence before him, he was clearly right to do so. To the extent that he referred to there being an evidential burden on the Defendant he was doing no more, in the particular circumstances of this case, and given that he had to make a decision on the evidence before him, than recognising (as he was entitled to) the apparent strength of Professor Middleton’s reasoned points and the consequent need for at least some reasoning from Professor Price to result in him not being persuaded that, on the balance of probabilities, the requisite test was met. He was also, in my view, clearly entitled to proceed upon the basis, again in the particular circumstances of this case, that the mere fact that the Defendant’s causation case was supported by reputable expert opinion, and that the Defendant’s expert would dispute the Claimant’s expert evidence at trial, did not mean that, on the evidence, the Claimant had failed to persuade him that the requisite test was met. ”[50]It was against that background that, in the particular circumstances of this case, I concluded that the proposed appeal had (and still has) no real prospect of success.”[58]The Farrington case was a decision by Martin Spencer J on an application for an interim payment in a claim arising out of a road traffic accident in which contributory negligence and medical causation were in issue.[59]In that case, the court refused an application for an interim payment in circumstances where there was an admitted brain injury (and the defendant had initially funded the claimant’s rehabilitation) but concerns were then raised about the nature and causation of the claimant’s ongoing symptoms. The claimant sought an interim payment of £450,000 which, in addition to the sums already received, would result in a total interim payment of approximately £710,000. The claimant relied on medical evidence from a neuropsychiatrist. The claimant accepted that the vast majority of the past costs (including significant care and case management costs) were disputed by the defendant but asked the court to accept that the dispute was likely to be decided in his favour at trial. A summary of the challenges to the claimant’s medical evidence, and the defendant’s expert evidence in response were summarised by the judge.

The judge then stated his conclusion at paragraphs 36 to 42:

[60]“36. In my judgment, the answer to this application lies in the principle set out in Eeles v Cobham and reiterated by Popplewell J in Smith v Bailey, namely that the objective of an award of interim payment is to ensure that the claimant is not kept out of his money to which he is entitled, whilst avoiding, "any risk of an overpayment”.[37]Thus, where there are genuine and substantive challenges to causation, in my judgment the court cannot award damages by assuming, whether on the balance of probabilities or otherwise, that the causation issues will be decided in favour of the claimant. This is not least because otherwise interim payment applications would run the risk of turning into mini trials of causation at an early stage and without the court hearing the necessary evidence it would need to hear in order to decide such issues.”[38]The approach to interim payments is informed by Part 25.7 of the Civil Procedure Rules which under sub-para.1 confines the circumstances in which an order for interim payment can be made to where either the defendant has admitted liability to pay damages or some other sum of money, or the claimant has obtained judgment against that defendant for damages to be assessed, or the court is satisfied that if the claim went to trial, the claimant would obtain judgment for a substantial amount of money.[39]The implication of this, is that the assumption where an interim payment is sought is that liability having been admitted or judgment having been entered, issues of causation are, by and large, resolved and all that remains is the quantification of the loss. However, it is sometimes the case that because some damage has been admitted and primary liability is admitted as here, the claimant is able to enter judgment but leaving over to the assessment of damages, significant areas of dispute in relation to causation. Which is the situation in this case.[40]In my judgment, Part 25.7 is not intended to cover situations where significant issues of causation remain at large. The court cannot assume, for example under 25.7(1)(c) that the claimant will obtain judgment for a substantial amount of money if, because causation is disputed, the defendant is contending that the amount which will be recovered is not substantial at all, as here.[41]There is and remains such a significant gap between what the claimant is seeking and what the defendant is conceding that were I to accede to this application, there would be a real risk of an overpayment. Even that states the position too highly in favour of the claimant, because it is not just a real risk that needs to be avoided, but within the authority of Eeles v Cobhamany risk which needs to be avoided.”

Parties’ submissions

[61]I have had the benefit of detailed written and oral submissions from both counsel on the applicable legal principles as well as the evidence. I do not propose to rehearse them in full in this short judgment, but I can sum up their overall positions briefly as follows.[62]Mr Tavares submitted that following the approach taken in Sellar-Elliot, the task of the court at this stage is to apply the relevant legal test in CPR 25.20 to the evidence before it at this hearing. This means in essence that I should assess the weight of the evidence that I now have from both parties’ causation experts and any other available evidence. By taking that approach, he contends that I should regard the evidence of Professor Scambler as significantly more persuasive than that of Dr Reardon and sufficient to support his present application. He also contended that to refuse the Claimant’s application would be ‘catastrophic’ for the family as the current care regime could no longer be sustained and, after April 2026, their current accommodation could no longer be afforded. He accepted that the Defendants had raised an issue of causation which required determination but urged the court not to refuse to make an interim order based on what he described as the Defendants’ speculative and extreme position.[63]Mr Willems submitted that the correct approach is the one set down by Martin Spencer J in the Farrington case and that, in these circumstances, I should not embark on a mini-trial of the genetic expert evidence at this stage. He submitted that in the light of the contested evidence on the issue of causation, I cannot be satisfied that the conditions set down in CPR 25.20 are met for the purpose of this further interim payment.

Discussion and conclusions

[64]There is no doubt that HDL suffered a severe traumatic brain injury in the accident requiring a craniotomy and subsequent further surgery. What is in dispute in this case is the likely long-term sequelae that may be expected from that injury and the extent to which the Claimant may have suffered from the same or similar symptoms, including behavioural and ASD-like symptoms in any event as a consequence of his genetic chromosomal abnormality.[65]I have carefully read all the experts reports filed for his hearing and I have already summarised the broad conclusions they have reached. I note that the two genetic experts are each very experienced experts in this field and have each provided reports with Part 35 declarations. They do however have slightly different types of expertise, with the Claimant’s expert, Professor Scambler, being a medically qualified research scientist and the Defendants’ expert, Dr Reardon, being a treating genetic clinician.[66]It appears to be common ground between the experts that this 22q11.2 genetic duplication can present with a wide range of features and severities, including features which are similar in nature to those currently experienced by the Claimant. Both experts refer to the fact that the genetic testing was arranged following a referral from the Claimant’s treating paediatrician a few months after the accident, although they place different weight on the significance of this fact. I also note that different medical experts have interpreted the written record of the referral differently. Having been provided with a copy of the referral form after the hearing, I can better understand the reasons for these discrepancies as some of the handwriting is difficult to decipher. It states on the referral form: “RTA 2020. [Seizures/Injuries] now resolved. Developmental delay – discrepancy between [growth/speech] delay and motor development.[67]The words in italics are not clear and have been interpreted differently by the parties. Whilst the precise wording may not be clear, the basis of the referral is plainly a concern about the cause of the Claimant’s developmental delay. I have also been provided with a copy of the genetic testing result form, which states:
“Microduplication of 22q11 (OMIM #608363) has been reported in association with a spectrum of clinical manifestations with wide variation in the severity of expression of the symptoms, from carriers with apparently normal phenotypes to patients with learning disability and congenital defects. This finding may be related to [HDL]’s clinical presentation.”
[68]No lay witness evidence has been filed yet, and the parties disagree as to the weight which can be attributed to the ASQ3 undertaken at just under 10 months, in late 2020. Indeed, even Professor Scambler, who relies on that assessment to support his conclusions, states that “an ASQ3 can only provide limited insight” but that “it is the single pre-injury assessment where we have peer-reviewed data to compare with HDL.”[69]I also note that Professor Scambler refers in his conclusion to ‘the great majority of the ongoing problems” being a direct consequence of traumatic brain injury." He does not therefore rule out the possibility of some ongoing contribution being made by the Claimant’s genetic condition. Similar comments are made by the Claimant’s other medical experts who defer to the genetic experts.[70]I am in a position where I do not have final reports from both genetic experts, nor the benefit of their full reasoning, nor the full pre-accident medical records nor any witness or video evidence from the parents or other family members. Indeed, most critically, I do not have the outcome of any expert discussions. So, if the Claimant’s approach were to be adopted, I would have to reach a decision on the basis of this limited and strongly contested expert evidence as to the likely conclusion that the trial judge would reach on causation, but without embarking on a mini-trial of causation.[71]I do not consider that can be the appropriate approach to take. The burden is on the Claimant to provide evidence in support of a further interim payment, particularly when payments totalling nearly £1million have already been paid. Furthermore, it is apparent from the language used in Eeles and summarised by Popplewell J in Smith that the purpose of making any interim payment is “to ensure that the claimant is not kept out of money to which he is entitled” or , as stated more bluntly in the final sentence of paragraph 43 in Eeles “not to keep the claimant out of his money” (emphasis added). The explicit references in both cases to the need to avoid any risk of overpayment by the defendant is simply another way of re-stating the basic principle underlying any interim payment, namely that the court should only be awarding sums which, on the balance of probabilities, the trial judge is bound to award to the claimant at the final hearing. In other words, any genuine doubt in relation to the recovery of any part of a claim must mean that it cannot be taken into account.[72]I am satisfied, having entered judgment, that the Claimant will succeed in the claim on liability, and will recover some damages relating to his traumatic brain injury. However, in the light of the competing expert causation evidence, I cannot be satisfied at this stage that the Claimant will recover the full extent of the damages claimed of £15-20 million, which, on the Claimant’s figures would result in a lump sum award in relation to general and special damages to date of approximately £1.8 million. If the Defendants’ causation evidence is accepted at trial, then the Defendants’ position is that the interim payments made already may be more than the recoverable damages, on the basis that the Claimant would have experienced similar symptoms and need similar levels of care as a result of developmental delay and behavioural symptoms caused by his chromosomal duplication in any event.[73]I consider that in the circumstances of a case such as this, the approach taken in Farrington must be the correct one. I am satisfied the Defendants have raised a genuine and substantive challenge to the Claimant’s claim in relation to the causation of his ongoing and future symptoms and that if their argument succeeded at trial, it would very significantly affect the value of this claim. This case can be contrasted with the case of Seller-Elliot, in which the defendant had chosen not to adduce any expert evidence in response to ‘compelling evidence’ from the claimant’s expert. In this case, the Claimant initially chose not to rely on any causation evidence in support of this application for an interim payment, despite the defence having plainly put the matter in issue, and only served their own genetic expert evidence after the Defendants had served a short form report from their genetic expert.[74]I understand that this decision is likely to create difficulties for those advising and caring for the Claimant, but despite all Mr Tavares’ oral and written submissions to this effect, it would not be appropriate for the court to make an interim order on the basis of those factors alone.[75]For all these reasons, in the particular circumstances of this case, I have come to the conclusion that the Claimant has not met the conditions for a further interim payment, and the application must be dismissed.[76]I have already indicated to the parties during the hearing that whatever decision I reached on the interim payment, it would be necessary to make a direction for an urgent preliminary issue hearing on causation as soon as possible.[77]I understand from the KB Listing office that a four-day hearing could be fixed in mid-April 2026, and I have already approved a directions order dated 19 December 2025 agreed by the parties in relation to the evidence required for that hearing. If any further directions are required the parties can apply to the allocated Master, or to Lambert J as the judge in charge of the Kings Bench List.