This website uses cookies

This website uses cookies to ensure you get the best experience. By using our website, you agree to our Privacy Policy

Trust the experts

Trust the experts


Recent judgments containing damning criticism of expert evidence provide a useful reminder of the duties experts owe to the court, write Kirsten Wall and Leila Grove

Litigation involving complex and specialist services often turns on evidence supplied by expert witnesses. This is particularly true of clinical negligence claims in which medical experts advise the court on matters of clinical practice. Cases often only settle once expert evidence has been exchanged and the strength of the medical experts’ arguments can be assessed.

When a case goes to trial, as is happening more and more in clinical negligence cases, the judge’s assessment of the experts’ evidence can be fundamental to the success, or otherwise, of the party instructing them. Over the last few years we are seeing an increasing number of cases where the judge is nothing less than scathing about the medical experts.

Given how central medical experts are to clinical negligence practice, and, let’s be honest, how much their fees can be, this is an issue that needs to be reviewed carefully so instructing solicitors can ensure their experts don’t make the same mistakes.

Where are the experts going wrong?

In the case of Watts v The Secretary of State for Health [2016] EWHC 2835 (QB), the claimant’s obstetric expert was criticised by His Honour Judge Peter Hughes QC for having ‘a serious lack of knowledge of clinical practice in 1993 and a worrying lack of appreciation of the importance of basing her opinions by the standards pertaining at that time’.

The case involved an action for a brachial plexus injury allegedly caused by the defendant’s negligence during delivery. In her report, the obstetric expert had referred to only one, American, textbook, which described shoulder dystocia as incapable of prediction before going on to detail the McRobert’s manoeuvre. However, the defendant’s experts gave evidence that the McRobert’s manoeuvre had not yet been adopted in the UK in 1993. When asked by the judge why she had only made reference to that textbook, the claimant’s expert answered that it was ‘the only textbook she had readily to hand’.

She later made it clear that she was aware of UK published textbooks which made no reference to the McRobert’s manoeuvre. HHJ Hughes described this expert’s approach to the use of literature as ‘unbalanced and highly misleading’.

Another clinical negligence judgment which addressed the reliability of a medical expert’s evidence was that of Cox v Secretary of State for Health [2016] EWHC 924 (QB). Again, it was the evidence of the claimant’s obstetric expert being scrutinised by the judge. The expert accepted in cross-examination that in an earlier report produced by him he had not included reference to the fact that there had been a failure to attempt a vaginal breech extraction. He conceded that the possibility of this allegation had only occurred to him some time later. Mr Justice Garnham was particularly troubled by the expert’s statement that he had been ‘persuaded’ to advance this issue, after a conference with counsel.

Garnham J equated this to making value judgments about what would be the better case to plead. He noted, ‘In my judgment the role of the expert witness is to provide expert evidence on the issues he is asked to address, rather than to concern himself with the conduct of the litigation.’

The potential independence of a medical expert came into question again in the case of Velarde v Guy’s and St Thomas NHS Foundation Trust [2017] EWHC 1250 (QB). Here, the defendant’s cardiology expert came under fire from Mr Justice Langstaff. It is clear that there had been much confusion about the interpretation of the medical records until just before the trial. However, the fact that the defendant’s expert sought to advance a new argument when it had already been agreed by counsel that this would not be done was heavily criticised. Langstaff J said that ‘as soon as he was in the witness box he began to advance that which he had earlier said he would not. I regret that I could not exclude his behaviour as being an attempt to manipulate court procedure so that he could advance a view which favoured the party calling him.’

Even more blatant an issue of partiality arose in EXP v Dr Charles Simon Barker [2015] EWHC 1289 (QB) and [2017] EWCA Civ 63, where it emerged that one of the defendant’s medical experts had known the defendant for a long time. They had trained together and also written a paper together which had not appeared on the expert’s list of publications. It was further revealed that the defendant himself had suggested that this expert be instructed. Mr Justice Parker said that he had come very close to ruling the expert’s evidence inadmissible in its entirety. The defendant lost the case and on appeal the Court of Appeal justices held that Parker J had been perfectly entitled to diminish the weight associated to the expert’s evidence given the concerns about partiality.

Even when the judge does not consider there to have been any attempt to inappropriately bring the case round to the instructing party’s side, a failure for the expert to properly consider the facts and documents available to him or her will also lead to criticism. This happened in the case of Harris v Johnson [2016] EWHC 3193 (QB), where the claimant’s expert neurosurgeon proceeded with his evidence on a misunderstanding about the instrument that was said to have caused the spinal injury during surgery. One was a sharp instrument and one was a blunt instrument. It became clear in cross-examination that his evidence had been based on a mistaken premise and he accepted in the witness box that he had a duty to check his assumption about the surgical instrument and his failure to do so was a breach of duty. In her judgment, Mrs Justice Andrews was highly critical and concluded that ‘at the very least this indicates that he did not read the material before him with the appropriate degree of care or ask the questions one would have expected him to ask to obtain clarification’.

Is the criticism by judges a new trend?

The expectation of independence is not. CPR 35 sets out that the duty of expert witnesses is primarily to the court, overriding any obligations they may have towards the party instructing them. Their role is to assist the court by providing objective opinions on the matters within their expertise, making it clear if an issue falls outside the scope of their expertise.

It may be that judges have simply had a larger forum to criticise expert evidence of late. More and more clinical negligence cases are being fought to trial and therefore we are seeing more medical experts being exposed to cross-examination.

It is clear from the criticisms levied that medical experts must be careful to show their evidence has been based on all the information available to them in the case. Any references they use will have to be carefully considered to ensure they are not only entirely relevant but also do not skew the picture. Consistency of the expert’s evidence is also important. All facts and case theories being advanced in the witness box will need to be present in the experts’ early reports and not just when they have taken the time to put their mind to the case fully when giving evidence in court becomes a reality.

These are issues those solicitors who instruct medical experts will need to keep at the forefront of their minds. Clearly, the experts themselves need to be live to these issues and one wonders whether the loss of expert immunity might result in the experts taking their duties in tort a little more seriously. If not, maybe a whole new area of work for medical experts will be born – advising on cases against other medical experts who fell foul of a judge at trial and who are now being sued by the party instructing them.

So, when working with medical experts:

  • Ask them to confirm they are not conflicted;

  • Ensure they consider fully all the necessary case documents;

  • Check that they are referring to appropriate literature; and

  • Try to avoid a pre-trial ‘light bulb’ moment that has not been addressed in served reports or pleadings.

Kirsten Wall is a partner and Leila Grove a trainee at Leigh Day