“[25] Where the quantification of loss depends on an assessment of events which did not happen the judge is left to assess the chances of the alternative scenario he is presented with. This has nothing to do with loss of chance as such. It is simply the judge making a realistic and reasoned assessment of a variety of circumstances in order to determine what the level of loss has been.”
“[188] As these citations show, despite Allied Maples having been the leading authority for nearly 20 years, this area is one that continues to cause real difficulties of classification and application. What I understand from these authorities can be summarised, with I hope suitable diffidence, as follows: (1) There is a difference between the question whether a loss has been caused by the wrong complained of, and if it has, the quantification of that loss. The fact that there is a distinction is in principle clear; what is not always clear is where the line is to be drawn. (2) Sometimes what the claimant has lost was only ever an opportunity to obtain something else, for example the chance to take part in a competition or the opportunity to bring litigation. Such an opportunity is a valuable right in itself, and what the claimant proves (on the balance of probabilities) is that he has lost that right; the assessment of the value of the right then depends on the chances of success. As Patten LJ says in Vasiliou at [21] this is because what has been lost is by definition the loss of a chance. It would obviously be wrong to value the right to take part in a competition at the value of the prize that might be won as the claimant never had a right to the prize, only the right to enter the competition. It would also be wrong to value the right to bring litigation as if it were bound to succeed, if, as is almost inevitably the case, the outcome of the litigation is uncertain. A claim with a prospect of success has a value, but until judgment has been obtained (and indeed it is clear that it can be successfully enforced) that value is not the same as the amount which would be awarded were it to succeed. (3) What Patten LJ makes clear, which had not I think been so clear before, is that this is not quite the same type of case as Allied Maples. In an Allied Maples case the claimant has not lost a valuable right, but he has lost the opportunity of gaining a benefit, albeit one which depends on a third party acting in a particular way. In such a case the claimant is not required to prove that the third party would have acted in that way, only that there was a real and substantial chance that he would. This is still a question of causation, not of quantification (see Vasiliou at [22], and also First Interstate Bank of California v Cohen Arnold & Co [1996] CLC 174 at 182 per Ward LJ, cited in Vasiliou at [43]); but if the claimant does establish that there was such a real and substantial chance, then when it come to quantification, his damages will be assessed not at 100% of the value of the benefit he would have obtained, but at the appropriate percentage having regard to the chances of his obtaining it. I only add the obvious point that in some cases, where the chance is found to be say 30%, the requirement that the claimant only need show that he has lost a real and substantial chance is beneficial to him (as if he had to prove how the third party would have acted on the balance of probabilities, he would recover nothing); but in other cases, where the chance is assessed at say 70%, it has the effect of only enabling him to recover 70% of the damages he otherwise would. But as I read the authorities, the claimant does not have a choice whether to adopt the Allied Maples approach; if the case is an Allied Maples type of case, this is the appropriate way to approach the issues of causation and quantification. (4) However, as Parabola and Vasiliou illustrate, there are other cases where the claimant does not seek to establish as a matter of causation that he has lost the opportunity of acquiring a specific benefit which is dependent on the actions of a third party; rather, he claims he has lost the opportunity to trade generally, and claims the loss of profits that he would have made. (5) It seems that in such a case the Court must first decide whether the claimant would have traded successfully. It is not entirely clear if this is part of the question of causation and a separate exercise from quantification; or whether it is to be regarded as part of the quantification exercise. Toulson LJ in Parabola at [23] fairly clearly treats the finding of Flaux J that “on a balance of probability Tangent would have traded profitably…” as part of the question of causation as he deals with it in the context of the claimant having first to establish an actionable head of loss, and coming before the “next task” which is “to quantify the loss”
“… Alan Howard had tasked our sales representatives with heavily promoting the EGO BOOST. From Pro Hair Live, 1 April, to … 14 June, (a period of approximately ten weeks) each of our sales representatives had dedicated in the region of 50% of their time promoting the EGO BOOST to their customers.”
“55. … In June 2012, we had not yet received our first order of EGO BOOST products. I had understood from my conversations with Stuart Laing that these had been due to arrive from China in May. Further, our representatives were becoming increasingly frustrated with EGO BOOST product. They found that their clients reported to them that Cloud Nine sales representatives had already told them that the EGO BOOST infringed the Cloud Nine product. 56. I felt the excitement for the EGO BOOST that we had managed to build up from Pro Hair Live at the beginning of April until around mid-May, had almost completely dissipated by mid-June. … … 60. The orders received by Team A in June, and on this basis the total estimated orders set out in the table at paragraph 58 above, show a huge drop-off. I attribute the drop-off in orders in June (and to the failure to meet and/or exceed our target in May) to the combination of the Alan Howard Letter, verbal threats made to our customers, and our lack of stock (and therefore inability to supply products to clients who had ordered them) which created a lack of confidence in the EGO BOOST, both at Alan Howard, and among our sales representatives.”
“The underlying concept for joint tortfeasance must be that the joint tortfeasor has been so involved in the commission of the tort as to make himself liable for the tort. Unless he has made the infringing act his own, he has not himself committed the tort. That notion seems to us what underlies all the decisions to which we were referred. If there is a common design or concerted action or otherwise a combination to secure the doing of the infringing acts, then each of the combiners has made the act his own and will be liable.”