We have seen several cases recently where judges have objected, in clear terms, to an expert trying to find “facts”. That is properly a matter for the trial judge.   It is worthwhile looking at the guidance and cases on this topic.  This is something that should be known by everyone who instructs and experts and, needless, to say every expert providing a report.


“Where there are material facts in dispute experts should express separate  opinions on each hypothesis put forward. They should not express a view in favour of one or other disputed version of the facts unless, as a result of particular expertise and experience, they consider one set of facts as being improbable or less probable, in which case they may express that view and should give reasons for holding it.”


Paragraph 57 of the Civil Justice Council Guidance for the instruction of Experts gives some useful guidance.

“57. When addressing questions of fact and opinion, experts should keep the
two separate. Experts must state those facts (whether assumed or otherwise)
upon which their opinions are based; experts should have primary regard to their
instructions (paragraphs 20-25 above). Experts must distinguish clearly between
those facts that they know to be true and those facts which they assume.
58. Where there are material facts in dispute experts should express separate
opinions on each hypothesis put forward. They should not express a view in
favour of one or other disputed version of the facts unless, as a result of
particular expertise and experience, they consider one set of facts as being
improbable or less probable, in which case they may express that view and
should give reasons for holding it.”


Prosser -v- British Airways

Prosser v British Airways Plc [2018] EW Misc B13

  “I add for completeness, that on a number of occasions Mr Evans [the medical expert]  made reference within his report to factual matters which were in dispute. It is clear that he formed his own opinion as to the reliability of the account given by the Claimant. I have not had regard to those comments within his report. The determination of factual issues and the assessment of witness evidence do not fall within his remit. They are matters that are for the court to determine having regard to all of the evidence available.”

Grant -v- Ralls

Mr Justice Snowden in Grant -v-Ralls [2016] EWHC 243 (Ch)


  • Mr. Lowry Mr. Lowry’s written reports went beyond the proper scope of an expert witness. He offered a variety of views in those reports, including, in his first report, his views as to whether the Directors’ decision to continue trading was justified by the prospects for trading and for obtaining investment from Mr. James. It also became apparent during his cross-examination that Mr. Lowry had relied to a significant extent upon materials produced for him by the Joint Liquidators without seeking to perform his own verification of the numbers, including in particular the figures which the Joint Liquidators indicated they had taken from the purchase ledger of the Company. That said, I thought that in giving his evidence, Mr. Lowry was balanced and prepared to accept points where appropriate – including that his original reports had strayed into areas beyond his remit.
  • Mr. Fanshawe Mr. Fanshawe was to some extent the opposite. His written reports were properly limited to matters within his expertise, and he had obviously conducted research and inquiries for himself throughout. But in giving his evidence I thought that Mr. Fanshawe was unduly argumentative – a feature that tended to obscure the points he was making – and tended to slip into giving evidence of factual matters that he had discovered during his investigations and discussions with the Directors and/or Mrs. Warman.
  • The net result is that overall I found the expert evidence very much less helpful in this case than it should have been. That was regrettable given the obvious importance of accuracy and clarity in such matters in a case of this type.


Mr Justice Coulson in Stagecoach Great Western Trains -v- Hind & Steel [2014] EWHC 1891 (TCC) was highly critical of the expert called by the claimant.

  1. General
  1. Not all of the expert evidence was satisfactory. In a case of this sort, what assists the court most is agreement about the state of the Tree before the incident and, in connection with the case against Mr Steel, a discussion of the various professional obligations which he may or may not have had. Instead, although there was a useful Joint Statement, the experts, particularly Mr Sheppard, spent far too much time dealing with matters of law and contentious matters of fact.There was also an uncomfortable amount of switching between that which the experts said an arboriculturalist should or could have done, and that which they suggested may be an obligation on the part of the landowner, without these boundaries ever being properly delineated and adhered to, and with no real regard for the fact that the latter issue was a matter for the court, not the experts[1].
Mr Sheppard
  1. Interview with Ms Hind
  1. When he visited the site in June 2010, Mr Sheppard (who had been instructed by the claimant and was already liaising with the claimant’s solicitor) briefly inspected the site and then had what was called an informal conversation with Ms Hind. As they were speaking, and rather betraying that alleged informality, Mr Sheppard made some rough notes on a small scrap of paper. He then went back to his car and expanded on his notes, principally by inserting questions into the notes that he had already made. There has been a long-running dispute about the accuracy of the notes. Moreover, although he had told Ms Hind that he would send her a copy of the notes for her to agree, he failed to do so. There was no explanation for this failure.
  1. When he was cross-examined by Mr Stead, on behalf of Ms Hind, it quickly became apparent that there were significant inaccuracies in the notes that Mr Sheppard had made. For example, Mr Sheppard noted that Ms Hind had said that she “never” went to the area of the garden where the Tree was. Ms Hind vehemently denied saying that, and stressed instead that she had told Mr Sheppard that she did go there (as part of her general observations of the trees), albeit that (because of the overgrown nature of the area) her visits were relatively rare. In cross-examination, he accepted that, although he could no longer remember the conversation, “rarely” was the word she had used. There was no explanation as to why, in his notes, he had deleted the word “rarely” and inserted the word “never”.
  1. There were numerous other errors and misleading changes of emphasis in Mr Sheppard’s notes. Again by way of example, Ms Hind gave evidence that, during that conversation, she told Mr Sheppard about the work which Mr Steel had done. Although Mr Sheppard could not remember the conversation, he continued to deny that she had made any mention of Mr Steel’s work. That seems inherently implausible, since she would have had no reason not to mention that work, particularly as she was talking about the trees in her own garden. That implausibility was then underlined by the fact that, in his first report, dated 2010, Mr Sheppard made express reference to the work done to the trees in the garden. There was no source for that information other than Ms Hind. This again demonstrated the inaccuracies of Mr Sheppard’s note-taking technique, and his equally unreliable recollection of the conversation.
  1. Still further, I noted that, in his reports, Mr Sheppard sets out a large number of things which he said Ms Hind had said to him during that interview. They are expressed as things which Ms Hind ‘stated’. But these were not matters which were referable even to the (inaccurate) notes that he had made. When Mr Stead cross-examined him about this, he accepted that these were his words, rather than Ms Hind’s, and were his ‘interpretation’ of what she said or would have said. That meant that the reports were doubly misleading, both because they failed accurately to report what Ms Hind had actually said, and because they identified her as saying things which were, in truth, just Mr Sheppard’s interpretation of what he thought she would have said.
  1. In the context of this case, these failures matter. Ms Hind, an intelligent woman and a keen gardener with a working knowledge of trees (see paragraphs 75-80 below), was portrayed in Mr Sheppard’s reports as someone who did not care about this Tree, or any of the trees in her garden at all, and had cheerfully let it all go to rack and ruin. There was even an echo of this stance in Mr Meredith Hardy’s closing submissions. I consider that this picture of Ms Hind was wholly misleading and inaccurate.
  1. I deprecate this aspect of the claimant’s case in the strongest terms. Save in exceptional circumstances, experts should not embark on this kind of fact-finding exercise, particularly when they perform it so unprofessionally. Matters of fact are for witnesses of fact, not for experts. Because a formal claim had already been made against Ms Hind by this time, she should at the very least have been interviewed by a solicitor and been given the opportunity of checking the resulting notes of that interview. Neither of these things happened. Inevitably, therefore, these failures meant that I regarded the remainder of Mr Sheppard’s evidence with considerable scepticism.
  1. Mr Sheppard’s ‘Trimming’
  1. Unhappily, my reservations about Mr Sheppard’s evidence did not end there. As will become apparent below, there is a significant issue in this case about whether Ms Hind should have regularly arranged for more detailed expert inspections of the trees at the property as a matter of course, or whether such inspections were only necessitated if there was some indication that there may have been a problem with the Tree. In his first report, at paragraph 7.5, Mr Sheppard accepted that the need for more detailed inspections was only triggered “if the tree displays unusual characteristics”. However, by the time that paragraph was repeated in his second report (and after the matter had been discussed with the claimant’s solicitors), it had been trimmed and the reference to the requirement for some form of trigger had been deleted entirely.
  1. Mr Sheppard said that this trimming was for reasons of space. I regret that I am wholly unable to accept that explanation: indeed, I regard it as so absurd as to constitute further evidence that Mr Sheppard was not acting as an independent expert in accordance with CPR Part 35. It is plain that paragraph 7.5 of Mr Sheppard’s first report was his honest belief, and, as we shall see, it is one that was in accordance with the authorities. But it was clearly detrimental to the claimant’s case (because of the difficulty in pointing to anything which indicated that this apparently healthy tree was, in fact, potentially unsafe). I find that this was the reason why this important passage was omitted from the second report. It again confirmed my view that Mr Sheppard’s expert evidence was unreliable.


In Hirtenstein -v- Hill Dickinson LLP [2014]  EWHC 2711 (Comm) the judge was highly critical of the expert. Considering expert evidence  in relation to the costs of repairs of a yacht.

Cost of repairs – Mr Smith’s evidence
  1. The claimants’ engineering expert, Mr Smith, assessed the cost of restoring the Yacht to its warranted condition in the sum of US$2,381,760. Mr Smith was provided with a spreadsheet listing all expenditure on the Yacht in the period July 2010 to April 2012, totalling US$2,850,118. The person (not identified by Mr Smith) who prepared the spreadsheet had already allocated the expenditure in columns between repairs, routine maintenance, upgrades and a category headed “questionable”. Mr Smith said that his instructions were to analyse the costs and to allocate them, including those marked as “questionable”, to the correct category.[4]
  2. None of the “questionable” items was classified by Mr Smith as an upgrade; nor did he classify as an upgrade any item which had been provisionally categorised as a repair or as routine maintenance. However, it is only necessary to read through the schedule of purported repair costs appended to Mr Smith’s report for it to be obvious that they include numerous items such as attorney’s fees (which Mr Smith was completely unable to explain) and a vast array of fittings and accoutrements, computer equipment and office supplies etc which are palpably unjustifiable. As these items evidently include a complete refit of the galley, it may truly be said, as Mr Tozzi, acting for the defendant, observed, that the claim includes the kitchen sink.
  3. The careless way in which Mr Smith approached his task can be gauged by the fact that approximately three pages of items which appeared in Mr Smith’s schedule of upgrades also appeared in his schedule of repairs. When asked about this, Mr Smith said that his error was to have included the sums in the schedule of upgrades. The sums in question included items such as guest bedding (US$13,549), main salon furniture (US$30,124), napkins and placement settings (US$17,174) and wine glasses (US$792) – to take just a few examples. Mr Smith’s explanation of why he considered that these and very many other sums which appeared, to say the least, questionable should be classified as repairs rather than upgrades was that he had assumed from the fact that they were purchased that it must have been necessary to purchase them in order to bring the Yacht up to the warranted standard, and not simply a choice of the owner to do so. Mr Smith agreed that he was therefore, in effect, assuming the answer to the question that he had been asked.
  4. Another unsatisfactory feature of Mr Smith’s evidence was that he attached to his supplemental report an appendix itemising expenditure totalling US$734,161 headed “costs for repairs to restore Il Sole to warranty standard (2)” which he was completely unable to explain. The appendix was not mentioned anywhere in the body of the report and Mr Smith had a “suspicion” that it might have been included in error.
  5. At the end of Mr Smith’s evidence, I offered him the opportunity to provide an explanation to the court before the end of the trial of how an appendix had come to be included as part of his report of which he claimed to have no knowledge. Mr Smith did not take up that opportunity, and I can therefore only infer that there is no explanation which exonerates Mr Smith of incompetence. On his showing in this case I do not consider that he is a fit person to act as an expert witness.
  6. In conclusion, I can attach no credence at all to the figures put forward by the claimants and rubber-stamped by Mr Smith for the alleged cost of repairs.”