21 It is no answer to this that the single expert could be cross-examined at the trial. Even if the cross-examination were such as to destroy Mr Hepworth's evidence, that would leave the Court and the plaintiff without critical evidence on a critical question. Indeed, it would be very much to the defendant's advantage that in a case where the plaintiff bears the onus of proving that the restriction had a substantial adverse effect, the choice might be between an expert who gave evidence to the effect that the adverse effect was not substantial, or (if that witness' testimony were destroyed successfully by cross-examination), there would be no evidence on the topic at all, so that the plaintiff would still fail.
22 Both parties made submissions about the delay which has been involved in the proceedings to this point as a result of the application for a single expert. First, it seems to me that an initial application for a single expert was an appropriate course. Hamilton J agreed. Lord Woolf explained why initially seeking a single expert is an appropriate course, and does not preclude a party who seeks it or participates in seeking it from subsequently seeking a separate expert report. Secondly, a significant part of the delay to date has been, as the plaintiffs submitted, occasioned by the defendant's opposition to applications on which the plaintiffs have ultimately succeeded - including the application before Hamilton J for a single expert, the application that I decided in February, and today's application. On the other hand, part of the delay has also been occasioned by the inappropriate manner in which the plaintiffs first sought to challenge Mr Hepworth's report. I do not consider that such delay as there has been on the part of the plaintiffs disqualifies them from at this stage seeking a separate expert. No prejudice to the defendant from that course has been articulated.
23 Accordingly, it seems to me that the justice of the case is that the plaintiff should have leave to obtain a report from a separate expert. However, consistent with the approach of Lord Woolf in Daniels v Walker it seems to me that the appropriate course is to permit the plaintiff (and the defendant, if so advised) to obtain and serve a separate expert's report. Consideration can then be given to a conference of experts, and the ultimate question of whether leave is granted to adduce competing evidence at the trial can be addressed once it is seen just what remains in issue.
24 I direct that each party may by 8 July 2009 serve the report of an expert valuer addressing the questions on which the party's single expert was asked to opine. I adjourn the proceedings to 10 July 2009 at 9.30am before me for further directions.
25 So far as the question of costs is concerned, the course adopted by Neuberger J has something to commend itself. His Honour recorded that, because the respondent opposed the application to call the new expert and because it might turn out that the new expert would be a waste of money irrespective of the outcome of the case, the Court should specifically consider at the end of the case whether, even if the appellants won, they should nonetheless pay the extra costs incurred by both sides as a result of the additional expert (or, if the respondents chose to call their expert, two additional experts). Subject to that reservation, it seems to me that the defendant must pay the plaintiffs' costs of the present application.
26 Accordingly, my order is that the defendant pay the plaintiffs' costs of the motion. I reserve for consideration of the trial judge the question whether, regardless of the outcome, the plaintiffs should pay the extra costs incurred by both sides as a result of any additional experts.