A v B

Expert evidence should ordinarily be admitted in the form in which it has been prepared, leaving the trial judge to assess its weight and disregard material outside the expert’s proper field. Excision or editing is generally unnecessary and disproportionate, save in a very clear case. The same approach applies whether the report falls within CPR Part 35 or concerns foreign law. A party must show real prejudice before the court will require an expert report or joint report to be reissued.

The defendant applied for an order declaring inadmissible specified passages of Professor Gaillard’s expert report and paragraph 17 of a joint expert report. The proceedings concerned the claimant’s application for recognition and enforcement of an arbitral award under section 103 of the Arbitration Act 1996. The defendant argued that parts of the reports improperly addressed construction, the application of law to facts and Article 5 of the New York Convention, and that the evidence was prejudicial. The central issue was whether the reports should be edited before a later hearing or left for the trial judge to evaluate.

1. The defendant’s application was dismissed. The reports were to remain before the court in their entirety for consideration at the March 2019 hearing.

2. The principle in Rogers v Hoyle [2014] EWCA Civ 257 was not confined to reports outside CPR Part 35, or to the rule in Hollington v F Hewthorn & Co Ltd [1943] KB 587. It applied more broadly where an expert report contained opinions on matters outside the expert’s proper role.

3. Except in a very clear case, there was little to gain from excluding or excising individual opinions. The proper course was for the whole report to be before the court, with the trial judge taking account only of material reflecting genuine expertise and disregarding material that was inadmissible or outside the expert’s remit.

4. The approach described in Moylett v Geldof [2018] EWHC 893 (Ch) was appropriate. Editing an expert report was undesirable where the report contained genuine expert evidence and the court could determine the weight to be given to particular passages at trial.

5. The defendant had not established real prejudice. Its submissions on admissibility could be advanced at the later hearing, and the judge hearing that application could disregard any inadmissible opinions. The existence of a joint report addressing the disputed matters further supported leaving both reports intact and avoiding unnecessary cost and delay.

6. The court should not pre-empt the merits of the adjournment application or the substantive enforcement issues. The reports could therefore be considered alongside the parties’ submissions at the hearing fixed for March 2019.

not stated in the judgment.