What happens when experts go rogue?

What happens when experts go rogue? 28 Jul

The appearance of expert witnesses to lend support to the Courts in civil litigation is well- established but their role in the dispute process is subject to increased scrutiny.

The Courts have taken a dim view of those experts who have failed to recognise the importance of their role within the litigation process and criticised others for seeking to stray beyond their remit – into territory reserved for judges.

CPR Part 35

Experts are permitted — or expected — to offer robust, well-reasoned opinions within their own field of expertise.  CPR Part 35 provides that the expert’s overriding duty is to the Court – not to the party by whom it is instructed.   In giving evidence, experts are expected to assist the Court by providing independent, impartial, and reasoned opinions in areas beyond the Court’s ordinary expertise.

As Lord Hamblen recently observed “Expert witnesses are not hired guns... They owe an overriding duty to the Court, and deviation from this is not just unethical, it is contemptuous.”

Three important decisions highlight the differing ways in which experts can fail to achieve the standards expected of them and the response issued by the judiciary.

Recent caselaw

First, we consider the decision of Liverpool Victoria Insurance Co Ltd v Zafar [2019] EWCA Civ 392. 

Following a road traffic accident, the claimant, Mr Iqbal, approached Dr. Zafar via his appointed solicitors to prepare a report of his injuries.  Dr Zafar concluded that the injury had resolved within a week or so of the incident and prognosis was a clean bill of health.  Mr Iqbal complained to his solicitor, stating he was suffering acute episodes 6-8 months post-accident.  Dr Zafar was invited to review his conclusions and, if he agreed, to provide a second (revised) report.  Without consulting his earlier notes or conducting a second examination Dr Zafar provided a revised report reflecting Mr Iqbal’s assessment of his own symptoms.  Given the relative strength of the second report, Mr Iqbal proceeded with his claim, serving the second report in support of his claim.

As with many such matters, the matter only came to light when Mr Iqbal’s solicitors submitted a draft trial bundle containing the first report.

Ultimately, this led to proceedings for contempt against both the solicitor and Dr Zafar.  In a first witness statement (completed with a Statement of Truth), Dr Zafar sought to blame colleagues for the error – submitting they had prepared the revised report without reference to him.  In  a second statement, Dr Zafar doubled down – suggesting that the second report reflected the true position and that his initial report had been mistaken.  He was imprisoned for contempt of Court.

The Court of Appeal was invited to revisit the sentence, upon referral from the Trial Judge. In considering matters, the Appeal Court noted “Solicitors and expert witnesses who act dishonestly in the evidence they give to the court, whether in support of such claims or otherwise, must expect a similar outcome [going to prison].”

In assessing the seriousness of Dr Zafar’s conduct, the Court compared his actions to those of a claimant who exaggerates a claim for monetary reward.   Having done so, the Court noted that:

“In the case of an expert witness, the fact that he or she is acting corruptly and makes the relevant false statement for reward, will make the case even more serious; but it will be a serious contempt… even if the expert witness stands to gain little financial reward by it. This is so because of the reliance placed on expert witnesses by the court, and because of the corresponding importance of the overriding duty which experts owe to the court.  Without seeking to lay down an inflexible rule, we take the view that an expert witness who recklessly makes a false statement in a report or witness statement verified by a statement of truth will usually be almost as culpable as an expert witness who does so intentionally.  This is so, because the expert witness knows that the court and the parties are dependent on his or her being truthful….. 

To abuse the trust placed in an expert witness by putting forward a statement which is in fact false, not caring whether it be true or not, is usually almost as serious a contempt of court as telling a deliberate lie.”

Dr Zafar’s sentence for contempt – assessed by the Court initially as six months imprisonment was found by the Appeal Court to be unduly lenient, albeit its length was not increased.  Dr Zafar was subsequently struck off as a GP.

In the next case, Davies-Gilbert v (1) Goacher (2) Chester [2022] EWHC 969, the Court was faced with resolving complex issues arising from the terms of restrictive covenants over land in East Sussex.

The Claimant was seeking an injunction to restrain the Defendants from carrying out further construction works, whilst the Defendants counter-claimed that the Claimant had unreasonably refused to consent to the development works.

The parties had been given permission to adduce expert evidence as to whether the proposed development would (i) affect the amenity of the land, (ii) be out of keeping with the surrounding land and/or (iii) affect future development opportunities.

The Claimant’s expert was a fervent advocate of the Sussex Style – the predominant style of building within the locale of the development. However, the expert failed to consider any buildings that were not constructed in that style and ignored those parts of his instructions that required him to consider anything other than Sussex style construction.  When questioned as to his actions, the expert suggested he had a discretion when compiling his evidence as to how to approach the task.

As for the Defendants’ expert, he placed significant weight upon the planning permissions that had been granted for the development.   He was, however, found by the Court to have been partisan in the Defendants’ favour and to have overstepped the bounds of his role by refusing to answer questions which were otherwise averse to his preferred view and, more critically, by opining upon factual matters relating to whether the Claimant ought to have reversed his objection to the granting of permission for the development.

Whilst not said expressly, the Court took the view that such matters were for the Judge to determine – where the expert ought to have confined himself solely to the three topics identified in the case management direction.

Where the Judge concluded that the Claimant’s expert had ignored his duties to the Court and the Defendants’ expert had failed to demonstrate objectivity and shown a lack of independence, indeed had been partisan, their respective evidence was to be “treated with great care” in assessing its value within the proceedings.

In the most recent decision of Hodgson v Hammond & Dieleman [2025] EWHC, a claim was brought for clinical negligence.  The claimant, Ms Hodgson, alleged that the First Defendant failed to undertake a pelvic examination or to arrange a further related scan, and that the Second Defendant failed to refer her for urgent examination thereafter.  The Claimant argued that if either of the defendants had undertaken or arranged for an urgent examination she would have been given antibiotics such that she would have recovered within two weeks and would have avoided a number of permanent, ongoing symptoms.

All parties called expert evidence.  Of particular interest was the evidence given by the Second Defendant’s expert.  The Court was perturbed that the expert failed to offer any concessions, in particular where the one perceived fact (upon which the expert’s testimony was based) had been fatally undermined during the Second Defendant’s own evidence.

In criticising the expert’s conduct, the Judge noted that the expert was (i)  trespassing on the judicial function to find, and rely on as a fact (or as her belief) matters that the second defendant was alleged to have considered during a specific consultation and, in providing her evidence, was “seeking to advocate on behalf of the Second Defendant, thus undermining her own independence.”

Ultimately the Court declined, despite being invited to do so, to disregard the expert’s evidence albeit the Court concluded that “there was no justification for them (the lack of concessions)…and they significantly undermine Dr Hall's credibility and independence in my eyes.” 

Edesia Law comment

Plainly, the role of an expert is viewed as one of much significance by the Courts.  It is essential that experts maintain their independence and restrict their evidence to those matters within their expertise.

An expert should not advocate upon behalf of any party and should ensure that the language and tone of a report is moderated so as not to read as akin to a skeleton argument.

As the cases demonstrate, particularly egregious conduct can lead to proceedings for contempt but even more modest departures from the duties of an expert (such as those highlighted in both Gilbert-Davies and Hodgson) can significantly undermine an expert’s credibility in the eyes of a Court and, ultimately, lead to an expert’s evidence being disregarded.

As the line between legal argument and expert opinion becomes more scrutinised, experts and lawyers alike must recognise that the Courts are listening not just to what is said, but how it is said.  The consequences for an expert — loss of credibility, adverse findings, and (possibly) wasted costs — are too significant to ignore.

 

July 2025

 

Simon Thomas is a Partner at Edesia Law