Despite their role as impartial providers of information, doctors acting as expert witnesses can themselves become subject to scrutiny.


The role of the medical expert is to give an impartial opinion to assist the court or a tribunal in coming to a decision about a case. They provide information and an assessment of the case based on specialised experience and knowledge, which the court relies upon in reaching its decision.

The Supreme Court (in the case of Jones v Kaney [2011] UKSC 13) has made clear that experts do not have the benefit of immunity, and can be sued for professional negligence. As a result, the MDU is occasionally asked to support members acting as medical experts.

The GMC emphasises the importance of being honest and trustworthy, and highlights that any evidence given or documents signed must not be false or misleading. These instructions are particularly important for the expert witness, whose role is to provide the court with an impartial assessment on areas in which they have particular expertise.

An expert can be called by either side in the hope that their opinion will favour that party's view. However, the expert must remember at all times that their function is to provide an unbiased opinion regardless of who hired them - they are not an advocate for either side, and their primary duty is to the court.

This may sometimes lead to confusion on the part of claimants, who, having hired an expert, may mistakenly be under the impression that the expert's role can bolster the claimant's opinion. An expert who does not make their position clear as an independent provider of expertise, and who subsequently adopts a position that does not reinforce the hiring party's view of the case, may find themselves the subject of a complaint or claim.

MDU audit

We analysed cases from 2014 through 2019 in which members sought our advice about their work as experts. We then performed a more detailed analysis of the 18 months between 1 January 2018 and 30 June 2019. As expected, most clinicians acting as experts are undertaking concomitant clinical work, but some, such as those who have retired, only undertake medico-legal work. Of the queries from those 18 months, nearly a quarter were raised by experts in psychiatry - followed by orthopaedics and those undertaking only medico-legal work, and then GPs.

Interestingly, a large number of queries related to concerns regarding data protection, with a spike in cases between April and July 2018. These cases tended to involve queries relating to complying with the General Data Protection Regulation (GDPR), which was implemented by an updated Data Protection Act on 25 May 2018. This illustrates that changes in legislation and regulation may cause concern for some clinicians.

In this period, there were several complaints made by patients who had been assessed by experts. Information about the outcome of the legal case for which the expert was instructed was, in most instances, not available, but the data did suggest these complaints came from patients who believed the expert report was insufficiently supportive, or who raised a concern about the attitude of the expert.

In two-thirds of these complaints, the expert had been instructed by the opposing party. This seemed to be the case in particular for psychiatrists, who were more likely to provide expertise in family court cases. Each of these complaints related to the expert's demeanour and attitude. Some cases featured a concern raised by the solicitors instructing the expert that the expert had changed their view, while in others concerns were raised about the expert's physical examination, which was felt to have been either inappropriate or to have caused further injury to the patient.

Within the 18 month period reviewed, only one case led to a GMC investigation. This related to the nature of the examination done in a personal injury claim. The GMC investigation was closed at the Rule 4 stage (the initial stage of a GMC fitness to practice investigation).

There were also a small number of civil claims, and the data showed that even where cases are closed there can still be considerable costs - for example, where legal instruction was required. Situations like this can occur when a patient feels that the expert report contains inaccuracies, and the MDU has seen a number of cases where a patient brought a claim alleging that the expert had made an error in their report which proved detrimental to the patient's case (such as where an expert had referred to the wrong reference range).

These claims can be costly, both in terms of the effort expended by the expert and the legal team and in terms of the cost incurred in defending them - and, as in one of these cases, settling the claim. It is therefore important to ensure both that the patient is aware of the expert's role and that the report is accurate, so that the expert is not placed in the uncomfortable position of potentially needing to defend their report or acknowledge an error.

Managing conflict with colleagues - course

MDU advice

Experts play a crucial role in providing expertise to a court or tribunal. They must be aware at all times that they are instructed to provide an independent opinion and guidance on questions within their particular field of expertise.

Whether approached by solicitors for the defence or the claimant, the role of the expert is to provide an independent assessment upon which a court may rely. It is important that an expert makes the patient aware of the independent nature of their role, and manages patient expectations. It would be prudent to explain to the patient that, in providing an objective assessment of the patient's case, the expert may be required to ask questions that the patient may find somewhat uncomfortable.

Experts should make clear that their opinion is impartial and that any report will reference all the information upon which the expert has relied. In this way, the likelihood of a litigant being unpleasantly surprised and disappointed with the expert's approach and conclusions may be minimised.

This page was correct at publication on 12/03/2021. Any guidance is intended as general guidance for members only. If you are a member and need specific advice relating to your own circumstances, please contact one of our advisers.