“88. … I do not accept Mr Ali has been forthcoming with the Court or Doctors Mundy and Trafford about the amount of alcohol he drank. I find the evidence of Mr Ali to be selfserving. He was not willing to admit that he was driving until the CCTV evidence was adduced. He has every incentive to downplay the amount he drank that evening. In line with Cracknell v Willis, there is no compelling evidence before me to support what Mr Ali says he had to drink and in the absence of such evidence, I am entitled to be sceptical of his account. I also rely on the two roadside breath test procedures which Mr Ali failed, the fact that he smelt of alcohol and that his eyes were glazed. I accept that the roadside procedures are not evidential in themselves but in my view, they corroborate that he was over the legal limit and that the machine was operating correctly. 89. There is a presumption that the machine is working correctly; the presumption is rebuttable. Essentially, other than Mr Ali’s claim that he did not drink enough to produce the reading that he did, there is no other cogent evidence before me to rebut the presumption. Therefore, on balance, I am not satisfied that the presumption has been rebutted. I am certain that the machine was working correctly. 90. Accordingly, I proceed on the assumption that the reading produced by the machine is reliable, that Mr Ali had a breach alcohol level of not less than 46 mcg in 100ml of breath. I find the case against Mr Ali proved beyond reasonable doubt.”
“5 Driving or being in charge of a motor vehicle with alcohol concentration above prescribed limit (1) If a person— (a) drives or attempts to drive a motor vehicle on a road or other public place, or (b) is in charge of a motor vehicle on a road or other public place, after consuming so much alcohol that the proportion of it in his breath, blood or urine exceeds the prescribed limit he is guilty of an offence.”
"Detention of persons affected by alcohol or a drug (1) The following provisions apply with respect to proceedings for an offence under section 5 or section 6 of this Act. (2) Evidence of the proportion of alcohol or any drug in a specimen of breath, blood or urine provided by the accused shall, in all cases, be taken into account, and it shall be assumed that the proportion of alcohol in the accused's breath, blood or urine at the time of the alleged offence was not less than in the specimen; but if the proceedings are for an offence under section 6 of this Act, or for an offence under section 5 of this Act in a case where the accused is alleged to have been unfit through drink, the assumption shall not be made if the accused proves - (a) that he consumed alcohol after he had ceased to drive, attempted to drive or be in charge of a motor vehicle on a road or other public place and before he provided the specimen; and (b) that had he not done so the proportion of alcohol in his breath, blood or urine would not have exceeded the prescribed limit and, if the proceedings are for an offence under section 5 of this Act, would not have been such as to impair his ability to drive properly."
“In the case of a breath specimen, there is of course a presumption that the machine is reliable. But if that presumption is challenged by relevant evidence, the magistrates will have to be satisfied that the machine has provided a reading upon which they can rely. … … I would hold that evidence which, if believed, provides material from which the inference can reasonably be drawn that the machine was unreliable is admissible. I am myself hopeful that the good sense of the magistrates and the realisation by the motoring public that approved breath testing machines are proving reliable will combine to ensure that few defendants will seek to challenge a breath analysis by spurious evidence of their consumption of alcohol. The magistrates will remember that the presumption of law is that the machine is reliable and they will no doubt look with a critical eye on evidence such as was produced by Hughes v. McConnell[1985] R.T.R. 244before being persuaded that it is not safe to rely upon the reading that it produces.”
“… If the Crown Court was to reject this critical evidence…, there had to be a rational basis for doing so but, as it seems to me, in the state of the evidence which then existed, there was no such basis or any other proper reason for rejecting his evidence.”
“20. It is important always in these cases to remember that the fact finders, both the district judge and the Crown Court, are entitled to disagree with an expert as they are entitled to disagree with any other factual proposition provided that there is a basis for doing so and provided that, if only shortly, they explain the basis of disagreement. After all, explaining the basis upon which an unchallenged expert's views are disagreed with is purely a discipline of a fact-finding approach to decision making itself.”
“12. …Evidence is required at least to raise the realistic possibility that the device on the occasion with which the court is concerned may have malfunctioned and produced a false reading. Assertions based merely on an alleged failure to comply with manufacturer's recommendations do not amount to such evidence.”
“I would hold that evidence which, if believed, provides material from which the inference can reasonably be drawn that the machine was unreliable is admissible.”