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Best of both worlds with PD57AC? High Court allows opinion evidence in factual witness statement

02 August 2023. Published by Rosy Gibson, Associate and Matthew Evans, Of Counsel

The High Court has allowed the witness statement of a factual witness even though the claimant had previously intended to instruct him as an expert and his statement contained opinion evidence (Polypipe Limited v Peter Russell Davidson) (1). The judge confirmed that such evidence is admissible where the witness is suitably qualified, but it will not be accorded the same weight as a formal expert report. Separately, this appears to be the first reported case in which the court accepted that permission for an extension to the deadline for expert reports could be made conditional on disclosure of any unserved report(s), though the court declined to prescribe that condition in this case.


The claim related to alleged breaches of warranties contained in an agreement for the sale by the defendant, Mr Davidson, of shares in a group of companies involved in the design, supply, manufacture, and installation of building protection products. The alleged breaches of warranty related to building failures at three projects in Ireland which caused an alleged loss in excess of £1.7 million.

After a case management conference, directions were given including permission for expert evidence in ground engineering to be adduced. However, the relevant order did not identify the specific experts. Before expert reports were exchanged, the claimant identified Mr Steven Wilson as its intended ground engineering expert, however, instead of submitting an expert report the claimant then submitted a factual witness statement from Mr Wilson. This statement described the forensic investigations he (and others) undertook in relation to failures at the site and the advice he gave the claimant in respect of them. It also related his views and opinions of the causes of those failures as well as describing the applicable industry standards.

When asked to explain why Mr Wilson's testimony was no longer proffered as expert evidence, the claimant explained that it considered Mr Wilson appeared insufficiently independent of it, having himself undertaken the investigations and given the advice described in his statement. Dissatisfied with this explanation, the defendant applied to have Mr Wilson's witness statement struck out in accordance with paragraph 5.3 of Practice Direction 57AC (the admissibility limb) and for disclosure of all reports, draft reports, and any material containing Mr Wilson's opinion in relation to the subject matter of the proceedings (the disclosure limb).


HHJ Hodge KC found against the defendant on both the admissibility and disclosure limbs of his application. 


The judge began by noting that although Practice Direction 57AC now applies to trial witness statements in proceedings pending before the Business and Property Courts, it has not changed the law concerning admissibility of witness evidence. The judge considered authorities in which witness statements had been struck out in whole or in part on the basis that the witness had strayed into inadmissible expressions of opinion. However, he noted that in those cases the witnesses were not qualified to express any expert opinion in the relevant field (2). Indeed, he noted that in one of the authorities, the judge (the then Chancellor of the High Court) had recognised that the rules as to witness statements and their contents were not rigid and that witnesses of fact may sometimes be able to give opinion evidence as part of their account of admissible factual evidence in order to provide a full and coherent explanation and account (3).

The judge adopted the following five principles, which were distilled from the relevant authorities:

  • There is no rigid rule that factual witness statement cannot contain opinion evidence: the rules about witness statements are not rigid statutes.
  • The object of the exclusion of opinion evidence is to avoid commentary by a witness of fact on matters of which they have no direct knowledge and can give no direct evidence. It may therefore be appropriate for a witness with relevant expertise and direct knowledge to include opinion in their evidence; they may lack objectivity but that goes to the weight to be given to the evidence, not its admissibility.
  • It can be helpful for the court to hear opinion evidence from a suitably qualified factual witness.
  • Opinion evidence in a factual witness statement is not inherently objectionable. It is only objectionable to accord it the same weight and status as expert evidence. 
  • Even if some evidence is inadmissible, the court has broad discretion and in the majority of cases it would be disproportionate to strike out a statement in its entirety where the offending paragraphs can be struck out or the judge can weigh the evidence appropriately.

Applying these principles to the case, the judge accepted that the factual and opinion matters in Mr Wilson's statement were so intertwined as to be inseparable but rejected the defendant's submission that the statement should therefore be struck out entirely. He was satisfied that the statement contained a mixture of both factual matters and permissible opinion on those facts of which Mr Wilson had either direct or hearsay knowledge, and permissible commentary on matters arising from those facts within Mr Wilson's own particular expertise. The judge therefore considered that Mr Wilson's statement fell within the scope permitted by the authorities, although he acknowledged that his expressions of opinion should not be afforded the same status as those in a formal expert report governed by CPR 35; the weight to be given to Mr Wilson's evidence was for the trial judge to decide and the court was likely to be assisted by the evidence of someone with contemporaneous involvement in the matter. 

The main point of difference between this case and those in which the relevant witness statements were struck out (in whole or part) was that Mr Wilson had relevant expertise in the field in which he offered his opinion.


The defendant's application also sought disclosure of Mr Wilson's reports and any material containing his opinion on the claim. Typically, such an order is made as a condition of the court's permission, allowing a party to change its expert whilst avoiding any possibility of 'expert shopping'. However, in this case the judge found that because the previous case management order had not specified Mr Wilson (or anyone) as the claimant's ground engineering expert, the change in expert was not a jurisdictional 'peg' which would allow the court to make such an order, nor was the judge persuaded that such an order could be made using the court's general case management powers. 

Rather, the judge held that he would have been able to make such an order as a condition of granting the extension of time sought (by both parties) for the exchange of expert reports. However, he went on to hold that it would have been inappropriate to do so in this instance as there was no reason to reject the claimant's explanation that it had chosen to proffer Mr Wilson's evidence as fact (rather than expert) evidence because he appeared too close to the business and interests of the claimant.  In effect, the judge was not persuaded that this was a case in which the claimant was, in fact, expert shopping. The judge noted that the defendant would have the opportunity to cross-examine Mr Wilson at trial and there was nothing preventing counsel for the defendant asking him whether he had ever entertained any views different from those set out in his witness statement.


Whilst this is a procedurally bespoke and unusual case, it demonstrates (again) that the admissibility of the content of trial witness statements is given a broader interpretation in practice than in theory. The court can be assisted by opinion evidence given in a factual witness statement if the witness has sufficient expertise and direct knowledge of the facts, which will counter-balance any possible subjectivity on the part of the witness by giving his or her evidence less weight than it would an independent expert instructed pursuant to CPR 35. That said, the judge appears to have taken a particularly generous approach to the change in nature of the claimant's evidence in this claim; an approach that may be unlikely to be replicated in other matters, and which may have been driven in part by the perception that the defendant was on a 'fishing expedition' for the claimant's unserved expert report(s).
Finally, it is worth noting that although the judge refused to order such disclosure, this appears to be the first reported case in which the court accepted that the grant of an extension of time could be made conditional on the disclosure of unserved expert reports if it appeared that one of the parties was 'expert shopping'.


(1) [2023] EWHC 1681 (Comm)
(2) JD Wetherspoon Plc v Harris [2013] EWHC 1088 (Ch); New Media Distribution Company SEZC v Kagalovsky [2018] EWHC 2742 (Ch)
(3) JD Wetherspoon Plc v Harris [2013] EWHC 1088 (Ch), paragraphs 40-41.