Day in the life of an Expert Witness

The detail of this judgment is for the specialists. It illustrates the challenges of proving that an infection has been caused by food poisoning at a hotel, and specifically the relevance of evidence as to other outbreaks in the area, trips out of the hotel, the records of illnesses suffered by other residents and audits of hotel food standards. The two learning points are oft-repeated ones and in this case of particular importance as some of the judge’s decisions depended on which expert’s evidence to accept.  

Rawson v TUI UK Ltd [2025] EWHC 2093 (KB) 

The claimant brought an action against two of its founding shareholders, and companies owned or controlled by them, seeking compensation for harm caused by their alleged participation in a fraudulent scheme. The forensic accounting expert for the first defendant failed to inform the court, until shortly before he gave evidence, that he had ceased to hold a key professional membership.  

JSC Commercial Bank Privatbank v Igor Valeryevich Kolomoisky & Ors [2025] EWHC 1987 (Ch)

The claimant asserted that the defendant was required to transfer title in a vessel at the expiry of the bareboat counterparty between them. The judge noted that the claimant’s witness on insurance broking had essentially no experience in the matter for expert evidence and his views appeared to be based on conversations with unidentified others, rather than his own experience of testable research.

This is a very important judgment for psychiatrists and psychologists who employ validity testing when assessing litigants. There were two experts, both psychiatrists. One employed validity tests. The other did not and she professed no experience of their use. The psychiatrist who employed them was a registered user of the tests for the administration of which he had been trained and had paid for a licence.

Brown v Morgan Sindall Construction and Infrastructure Ltd [2025] EWHC 2204 (KB) 

The claimant alleged that the vibrating tools he used while employed by the defendant caused Hand-Arm Vibration Syndrome. The judge criticised one of the medical experts for looking for answers that supported his strong views on the subject, rather than obtaining a reliable history from the claimant.

In this case of suspected non-accidental injuries to an infant, only one of the experts was required to give evidence. This was Professor Fleming and as the judge found that he gave his evidence in his characteristically understated and calm fashion and was precise, knowledgeable and reasonable in his evidence, it is set out here in full as a model.

The case also illustrates how the expertise of clinical geneticists, endocrinologists, haematologists, neonatologists, paediatricians and radiologists can all be necessary where non-accidental injury of a child is the issue.

The Claimant brought a claim for compensation in the UK after he was hit by an uninsured driver while on holiday in Mallorca and suffered major injuries, including severe brain injuries. The court found the evidence of several of the experts to be unsatisfactory leading the judge to preface his assessment of the expert witnesses with the observation that “[t]he court is not bound by the conclusions of any expert if it offends logic and common sense. We do not have trial by experts.”

This is an important case for three reasons.

First, it found that a general practitioner, giving evidence about the depressive disorder diagnosed in primary care, was giving expert evidence. Second, it illustrates the difficulties for courts and tribunals arising from the looseness with which some medical professionals, and most laypeople, use such terms as "depression" ("clinical" or otherwise), "anxiety" and "stress" and to which list can be added, also for the benefit of surgeons, “shock”. Third, it is a good illustration of the approach likely to be taken in an Employment Tribunal disability case.

J v DLA Piper UK LLP [2010] UKEAT 0263 09 1506