The High Court decision in Muyepa v Ministry of Defence [2022] EWHC 2648 (KB), is a cautionary tale for expert witnesses (known as skilled witnesses in Scotland) and a good reminder that such witnesses should provide impartial, unbiased evidence.

Facts and Decision

The claimant alleged he had been injured while serving in the armed forces. He sued the Ministry of Defence for £2.9 million in connection with those injuries. However, after an evidential hearing, the judge found that the claimant had greatly exaggerated the extent of his injuries and the action was dismissed on the grounds of fundamental dishonesty.

Mr Justice Cotter also criticised the evidence given by the claimant's care expert. During her evidence, the claimant's wife admitted that she and the claimant had lied to the care expert, and that that they had done so in an attempt to increase the amount of care recommended by the expert and thus the value of the claim. In light of that admission, the expert was given an opportunity to reassess her valuation of the claimant's care costs. However, she chose not to do so. She also failed to amend her report or to provide any recalculated estimates prior to giving her own evidence. The judge commented on "how unsatisfactory" this was.

Mr Justice Cotter also found, separately, that the expert had made a number of recommendations in relation to the claimant's future care needs which she failed to justify. For example, the expert recommended a "riser recliner chair", at a cost of £1,100, so that the claimant could "stretch his back out" when the alleged injuries had no impact on the claimant's back. She also recommended a "whirlpool bath" at a cost of £10,000, with no explanation as to why this was required. During her oral evidence, the expert eventually conceded that some aspects of her report, and certain recommendations contained within it, were "ridiculous".

She confirmed that she had been preparing reports and giving evidence solely on behalf of claimants for nine years. In relation to this, Mr Justice Cotter commented:

"She recognised the understandable concern a Court will have as to the risks that arise when an expert’s workload (and income) is solely for one side to litigation. In my view the risk came to fruition and the reports she prepared contained some partisan views designed to maximise damages for the Claimant rather than recommendations made, as they should have been, after balanced and objective application of the relevant principles."

Unsurprisingly, the court had "no hesitation" in preferring the evidence of the defendant's care expert, who was a "helpful...experienced expert with a balance of instructions roughly two thirds defendant and one third claimant."

In his judgment, Mr Justice Cotter emphasised the need for expert witnesses to remain unbiased and independent notwithstanding any pressures to provide evidence favourable to their instructing party. "Significant reliance may be placed on their analysis" so they must be "objective and non-partisan if a just outcome is to be achieved in the litigation". Experts have an "overriding duty to the court to help on matters within their expertise". They must "constantly remind themselves through the litigation process that they are not part of the claimant’s or defendant’s “team” with their role being the securing and maximising, or avoiding or minimising, a claim for damages".

Analysis and Comment

In discussing the duties owed to the court by expert witnesses, the judge referred to the Civil Procedure Rules which do not apply in Scotland. However, the requirements for expert witnesses set out in those rules are, in all material aspects, identical to the equivalent principles which apply in Scotland and which were confirmed by the Supreme Court in Kennedy v Cordia (Services) LLP [2016] UKSC 6 (you can read our blog about that decision here). In Kennedy, the Supreme Court set out four considerations relevant to the admissibility of expert evidence; one was that the expert must be impartial in their presentation and assessment of the evidence. The Supreme Court in Kennedy also confirmed that experts should be independent, unbiased and should never assume the role of an advocate.

The Muyepa case is (hopefully) an extreme example of an expert witness giving impartial evidence, but it illustrates what can happen if experts lose sight of their proper role in litigation, and their overriding duties to the court. The case also demonstrates the benefit of instructing experts who have a practice balanced between claimant and defender work.


Kate Donachie

Legal Director

Laura McMillan

Partner & Director of Advocacy

Stephen Kirk

Trainee Solicitor