This was a significant and well reported patent case which was determined in the Intellectual Property List within the High Court last autumn.   

The technical aspects of the case required significant expert input from the panel involved.  The cross-examinations performed by leading Counsel for the parties were lengthy and complicated.  This led to confusion over what evidence was given when the transcripts were re-visited on subsequent trial days. The case shows how consideration should be given to experts who are being cross-examined so not to overload them with questions and information on the stand.

Experts are advised, if possible, to avoid expressing opinions on the basis of possibility. The usually applicable stand of proof is the civil standard – the balance of probabilities or more probable than not. The criminal standard of proof is beyond reasonable doubt (and not beyond all reasonable [sic] doubt as it is sometimes misquoted). In this case it was submitted that the expert used the terms "possibility", "high possibility" and "extremely high possibility" interchangeably and that this was insufficient to satisfy the criminal standard of proof. However, when the court analysed the expert’s report as a whole, it was clear that a tribunal of fact could safely conclude that the criminal standard of proof was satisfied.

Government of Japan v Chappell [2025] EWHC 166 

The detail of this case is of relevance to dental experts and attention is drawn to the clarity and particularity with which Professor Harding set out the instances of treatment of the Claimant which was below the standard she could reasonably have expected and then identified the consequences thereof. There is a gastroenterological and pharmacological dimension to the case because it was alleged, and found, that the pain resulting from the negligent dental treatment necessitated treatment with NAISDs which caused ischaemic colitis. 

Bailey v Bijlani [2025] EWHC 175 (KB)

The detail of this judgment is for experts who conduct capacity assessments. Two points arise of more general interest.

First, the expert, who had been involved in the case for six years, changed her opinion. In the language of the court it was a 180^o degree change. The court thought that this called for a greater discussion in the analysis section of the report. This seems to have been that section of the report for which experts use the heading ‘Facts and assumed facts’ or ‘Factual analysis’. Second, the expert suggested that the issues, or some of the issues, in the case could be resolved by invoking the inherent jurisdiction of the court. But there had been no application for the exercise of the court's inherent jurisdiction, it was not referred to in the letter of instruction, and it might not – as a matter of law – have been available. This is a good example of the advice to experts to leave the law to the lawyers.  

Calderdale Metropolitan Borough Council v LS [2025] EWCOP 10 (T3)

In the 11th episode of the Expert Matters Podcast, we take a look at how AI is being used by Expert Witnesses. We discuss general developments related to AI in the legal sector, hear from EWI member and computer expert Richard Marshall, listen to some of the ways AI is currently being used by Expert Witnesses, and discuss some dos and don'ts when using AI. As usual, we begin with our segment on 'What's going on at EWI?' and end with 'Newsreel', a quick fire discussion of the key things you need to know this month. 

The expert paediatrician in this case misidentified and confused twins when reading the primary medical disclose. This fundamental error was of seminal importance in this case because the twins had very different birth and post-birth experiences, with one being much weaker and more vulnerable than the other.  The judge noted that the cross-examination of the expert was nothing short of a demolition of the expert’s evidence.

LB Croydon v D (critical scrutiny of the paedeatric overview)

Mr Simon Britten, immediate past chair of the British Orthopaedic Association Medico-legal Committee, in his foreword to the forthcoming Expert Musculoskeletal and Orthopaedic Evidence, refers to how giving evidence one Monday in a case of tibial fracture, missed compartment syndrome and subsequent amputation, he was asked when he had last fixed a tibial fracture. Understandably, he said that the judge’s reaction to his answer ‘last Friday’ appeared to be a promising start. However, it is not a hard and fast rule that the healthcare expert should have experience, or recent experience, of performing the procedure or operation in issue. This case illustrates it.

Advanced Hair Technology Ltd v Revenue and Customs (VAT - whether hair transplants to treat androgenetic alopecia are exempt supplies of medical care) [2025] UKFTT 241 (TC) 

The complexities of this case required both parties to engage expert quantity surveyors.  Both sides approached their instructions to their expert from different angles which caused difficulties at trial.  This explained why the valuations were worlds apart (or as the judge commented they had a “manifestly excessive difference”) and needed some careful scrutiny and assessment by the judge. Whilst the approach of examining both valuations is very case specific, there are some fundamental tests which can be taken away.  An objective test was used several times as a benchmark looking at the scope of works that a ‘reasonable owner’ or ‘purchaser’ would require.  The key legal issue of “proportionality” was also visited frequently throughout the assessment of valuations. 

Iya Patarkatsishvili & Anor v William Woodward-Fisher [2025] EWHC 265 (Ch)

The parties sought permission to rely on expert evidence from three experts in respect of the claimant’s tazkira, an official identity document issued by the former Islamic Republic of Afghanistan. The judge found the first proposed expert’s evidence to be hearsay, and (if the proceeding continued) directed the parties to re-serve the second expert’s report with evidence for which permission had not been given excised, and to re-serve the third expert’s report with a compliant declaration.  

MS, R (on the application of) v Kent County Council [2024] EWHC 2661 (Admin)

In this patent case, the judge noted that neither expert was a native English speaker and both had difficulties with questions put to them during cross-examination. The misstep of one expert over the word “buckling”, which he had used in his report, and his use of a translator during cross-examination for reference, led the judge to approach his written evidence with a degree of caution.

Salts Healthcare Limited v Pelican Healthcare Limited [2025] EWHC 497 (Pat)