The Claimant asserted that the Defendant had infringed their patent for an electric shower-waster pump and control unit. The trial related to liability only. Both sides criticised the other’s expert. The Judge rejected these criticisms noting that, while he reached conclusions that differed from the experts in various places, he did not consider either expert to be unreliable or that their evidence generally should be discounted.

Catherine Jago is an oil and commodities Expert Witness with nearly four decades of experience in the field. She started her career at BP before working as an oil journalist, broker and trader. In 2023 she founded her own international Expert Witness practice, CJH Experts, which carries between 20 and 30 live instructions at any one time. Here, she tells us how she came to the role in unexpected circumstances, what makes a truly good Expert, and why independence is never negotiable.

The decision in O'Neill v Scottish Ambulance Service Board [2025] CSOH 17 provides important guidance on the legal and professional standards applicable to remote clinical triage. The court reaffirmed that clinicians conducting telephone assessments are held to the same professional standards as those undertaking face-to-face consultations.

The importance of this case is that it confirms that medical practitioners providing evidence as to a patient’s fitness to participate in legal proceedings are providing expert evidence. It may be termed ‘professional’ evidence but it is expert evidence. It is expert evidence because the medical practitioner is assisting the court as to matters outside the knowledge and experience of the court. In this case the court depended on the applicant’s general practitioner to understand complex PTSD, spiking of blood pressure to dangerous levels and dysphonia and how they made the applicant unfit to participate in her appeal against the order made by the court as to the disposal of her son’s ashes.

Julie Karen Hoarean v Paul Anthony Read [2026] EWHC 763 (Ch)

The Petitioner, who was one of 15 candidates in an English Parliamentary By-Election, alleged that his vote count of 50 was fraudulently pre-determined. The expert statistician for the Petitioner based his opinion solely on the evidence of the Petitioner, which was contested. He was unaware of the contents of the Respondents’ witness statements and had not taken them into account.

At a time when psychologists in particular are concerned about psychological evidence being given by psychologists who are unregulated, this case illustrates the risks when an ‘independent’ social worker gives psychological evidence.

The learning points are of general application. The specifics of the case are for psychologists, psychiatrists and social workers.

Coventry City Council v XX [2024] EWFC 249 (B) 

Hon Mr Justice Trower provides invaluable guidance for Expert Witnesses at the 2024 the Sir Michael Davies lecture.

The judge found that it was entirely artificial to think that sharing a platform speaking at a seminar during (in the case of one expert) or before (in the case of the other) giving evidence would have any effect or impact on the evidence of two expert witnesses in urogynaecology.

An expert is entitled to revise his or her opinion in light of a judge's finding as to what is or is not required in order to comply with particular regulations or equivalent regulatory standards.

The cout found that a financial expert's report was inadmissible as evidence because he was not properly independent or objective, while very little weight could be attributed to the report of an employment expert because he lacked expertise in the area in which he purported to give expert evidence.