Day in the life of an Expert Witness

The Claimant alleged that an accident five years earlier was the cause of the amputation of his lower leg. The judge criticised the Claimant’s orthopaedic expert, Professor H, for demonstrating at times a rather ‘loose approach’ to his expert evidence and a closed mindedness towards his evidence.

It is not easy to appreciate the significance of this judgment for experts in general without reading the summary so the ‘Commentary’ is at the end. The neuropsychological test results are perhaps not of particular interest to psychologists and psychiatrists at this stage in the proceedings but may become so if the case does not settle and it goes to trial. 

Perrin v Walsh (Rev1) [2025] EWHC 2536 (KB)

The Claimant’s father and litigation friend alleged that the medical practitioners treating his son were negligent in not promptly carrying out an ultrasound on his head, after he had been admitted to hospital with head injuries. The judge found that the expert for the Claimant was, to an extent, seeking to fight his corner rather than taking a dispassionate approach to the issues raised.

The appellant is a citizen of Iraq. He appealed against the decision of a First-tier Tribunal Judge who dismissed his appeal against the respondent's decision to refuse his protection claim. The appellant raised three grounds of appeal including that the Judge failed to properly take into account the medical evidence.The Upper Tribunal found that it was clear from the Tribunal Judge's decision that he rejected the medical evidence in a comprehensive and detailed way. This was not, contrary to the grounds of appeal, the Judge ignoring the medical evidence when he was making his credibility findings. As such the Tribunal found that the Judge did not materially err as advanced, and his decision stands.

JK v The Secretary of State for the Home Department [2025] UKAITUR UI2024003446

The Claimants alleged that dust, noise and odour emitted by the defendant’s factory over a prolonged period constituted a legal nuisance. The judge was critical of the Claimants’ experts for departing from the initial common approach when the initial results had been adverse to their clients’ case.

There are some general learning points for all experts but otherwise this is for neurosurgeons. It is another road traffic accident personal injury case in which the court needed the assistance of neurosurgeons, or at least it would have done but for the fact that it made a finding which made it unnecessary to consider the neurosurgical evidence before reaching a judgment. The nature of the injuries sustained by the claimant were not in dispute. What was in dispute, but ultimately irrelevant, was what the child’s injuries would have been if the driver of the vehicle had been driving (non-negligently) at a lower speed than he was. It was on this point that the neurosurgical experts disagreed.

MW v Wilkinson [2025] EWHC 2300 (KB) 

Following last month’s case update by Professor Keith Rix of Brown v Morgan Sindall, several experts have offered further reflections on the use of validity testing in medico-legal assessment. Commentaries from Professor Michael Kopelman (neuropsychiatry), Dr Karen Addy (neuropsychology), Mr Daniel Friedland (neuropsychology) and Dr Kathryn Newns (clinical psychology) were published in the MAEP Expert Witness Healthcare Matters newsletter, coordinated by Professor Rix.

This follow-up brings together the key points emerging across disciplines. It also clarifies several areas regarding the early learning points given in the September case update. The discussion in this article refines those conclusions and reflects current multidisciplinary consensus. 

Familiar to all experts, this case illustrates how personal injury claimants can attempt to maximise their claim by dishonestly reporting symptoms and disabilities. There are few honest and experienced experts who can say that they have never been deceived by a personal injury claimant. The more experienced will avoid saying that the claimant appeared genuine, that they had no reason to doubt their account, or that they appeared to be honestly reporting their difficulties.

What assisted the court in this case was the findings of the experts that the claimant’s presentation was not supported by the objective findings.

This case has a more important message. An expert, having given an opinion that he has no reason to doubt a claimant’s veracity (not just a conclusion on the balance of probabilities, but beyond reasonable doubt), when he comes to change his mind, is under a duty to the court positively to make clear that he no longer holds that opinion. It is not sufficient to leave the judge to read between the lines. 

Debbie O'Connell v The Ministry of Defence [2025] EWHC 2301 (KB)