Opinion: ‘I’ll have to take your word for it’ – undisputed expert evidence in the UK courts

Opinion: 'I’ll have to take your word for it' – undisputed expert evidence in the UK courts

Pictured (L-R): Stefanie Johnston, Iain Franklin and Imogen Webb

Stefanie Johnston, Iain Franklin and Imogen Webb from Ince & Co’s London and Scotland offices consider TUI Ltd v Griffiths (Supreme Court Appeal from [2021] EWCA Civ 1442), given its implications for UK-wide practice.

The Supreme Court has heard an important case on the courts’ approach to ‘uncontroverted’ or undisputed expert evidence. Mr Griffiths’ claim was dismissed at first instance and, on appeal, the High Court reversed the decision and found in the claimant’s favour. The claim then proceeded to the Court of Appeal in 2021, where TUI Ltd (TUI) was successful in reversing the High Court’s finding, based on its argument that Mr Griffiths’ expert evidence should not be accepted, despite not serving any expert evidence of its own. Mr Griffiths now appeals to the Supreme Court.


As he boarded a plane to Turkey in August 2014, Mr Griffiths can hardly have imagined that his holiday would lead him to litigation in the Supreme Court.

He had purchased from TUI an all-inclusive 14-day holiday. At the airport he ate a burger from a well-known chain and thereafter he took all of his meals at the hotel apart from one meal eaten in the local town.

Mr Griffiths fell ill on the second day of his holiday with stomach cramps and diarrhoea. His condition worsened until he required hospital treatment in the course of which he was diagnosed with acute gastroenteritis. Mr Griffiths’ claim came to be that food, drink or fluids consumed at the hotel had caused his illness. TUI denied this was the case.

The expert evidence

At trial in the County Court, TUI raised no expert evidence. Mr Griffiths relied on evidence from a consultant microbiologist on the issue of causation of his illness, as well as gastroenterology evidence regarding condition and prognosis. The microbiologist was not cross-examined and his evidence was contained within his report and written responses to questions posed by TUI. The report itself was short, being described by the County Court judge as “minimalist”. The report concluded the most likely cause of Mr Griffiths’ illness was contaminated food or fluid from the hotel.

In closing submissions, TUI made a number of criticisms of the microbiologist’s report. Essentially, it was argued that the microbiologist’s reasoning was insufficient to persuade the court to make a finding in line with his conclusions.

Uncontroverted expert evidence

Expert evidence is uncontroverted where no evidence is served to contradict it during the trial and the expert is not cross examined. In those circumstances, the first time a party hears criticism of their expert’s report may well be during closing submissions at trial.

The Supreme Court has previously indicated that evidence from an expert which amounts to mere assertion is worthless, (Kennedy v Cordia, [2016] UKSC 6 at para 48). The microbiologist’s report in this case was not considered to amount to mere assertion, but it was considered to be deficient due to lack of detail and reasoning. Therefore, the question which arose sharply in this case is whether it is possible for the court to weigh the evidence of an uncontroverted report which is validly criticisable, although more than mere assertion.

The High Court had found that where a report was uncontroverted, the court was not entitled to analyse it in the same way as a disputed expert report. In effect, if a report fulfilled the required minimum standards of CPR 35, then it should be accepted.

The majority in the Court of Appeal disagreed with this “bright line” approach and considered that judges had discretion as to whether to accept the evidence, as it “all depends upon all of the circumstances of the case, the nature of the report itself and the purpose for which it is being used in the claim” ([2021] EWCA Civ 1442 judgment of Asplin LJ at para 40). Where the evidence contained logical conclusions from a joint expert, (instructed by both parties), or two experts that agreed, the court would be unlikely to reject the evidence, although it is not restricted from doing so if cogent reasons are given.

Arguments raised about the ‘fairness’ of expert evidence being challenged in closing submissions did not persuade the court, as the defendant is entitled to submit that the case has not been proven to the required standard. The burden is on a party serving evidence to ensure it is satisfactory.


The principal lesson to be learned from the Court of Appeal’s decision is that legal representatives must work closely with experts to ensure their reports not only comply with CPR 35 requirements but also contain sufficient reasoning for their conclusions. On the current state of the law, failure to do so will pose a real risk that the report will not satisfy the relevant burden of proof. Evidence will not necessarily be accepted by the court, simply because it is uncontroverted.

Equally, the reason why the issue of uncontroverted expert evidence arose in this case is because TUI did not serve its own expert evidence in line with the court directions, (and a subsequent application for relief from sanctions was dismissed). The prospects of challenging the opposing party’s expert evidence will plainly be improved if robust expert evidence is served to dispute it.

The decision of the Supreme Court is awaited with interest.

Stefanie Johnston (dual-qualified partner), Iain Franklin (managing associate) and Imogen Webb (managing associate) are lawyers at Ince & Co

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