THE ROLE OF THE EXPERT WITNESS IN FINDING FACTS AND ASSESSING CREDIBILITY
The recent posts on the assessment of witness credibility led an expert witness to enquire whether it was the function of an expert to comment on issues relating to credibility. There have been a number of cases where judges have considered the effect of expert witnesses commenting on primary facts. The judiciary have traditionally, and rightly, guarded their role as primary fact finder. However this does not appear to stop experts giving a, usually unwanted and highly unhelpful, “helping hand”.
“…experts should not embark on this kind of fact-finding exercise, particularly when they perform it so unprofessionally. Matters of fact are for witnesses of fact, not for experts.”
“It is no part of an orthopaedic expert’s speciality to suggest who should be believed and why,”
AN APPROACH THAT WAS “AS MUCH ONE OF ADVOCACY AS IT WAS EXPERT OPINION”
In Mohidin -v- Commissioner of Police for the Metropolis  EWHC 2740 (QB) the judge commented on one of the medical experts for the claimant.
Dr Jarman adopted an approach to his reports on all three Claimants which, to be frank, was as much one of advocacy as it was expert opinion, although once winnowed of the advocacy it contained much of value. He also trespassed at times into making findings of fact about credibility which should have been left to the court. But his central point in both cases was that Dr Lord depended wholly on the veracity of the respective Claimant, and that there was no evidence independent of him to support the diagnosis.
VIEWS OF THE EXPERTS OF “MODERATE WEIGHT”
In Susan Saunderson & Others -v- Sonae Industria (UK) Ltd  EWCA 2264 (QB) Mr Justice Jay considered a submission that since the claimant’s medical experts accepted that the claimants were genuine this finding should have some weight.
“I have already said that I will be taking on board all the available evidence, but an issue does arise as to the weight to be given to expert clinical opinion on the Claimants’ side that, generally speaking, the Test Claimants were honest individuals who gave reliable accounts. Dr Swift and Dr August spoke in different terms but to the same effect of intuitive judgments forged from lengthy experience in history-taking and clinical examinations. The Defendant’s experts, on the other hand, deferred to me on these matters.
244. I have thought very carefully about this last point, but I cannot agree with Mr Redfern that I should be affording “significant weight” to these expressions of opinion. It is striking in this case that by the stage any Test Claimant was seen by the experts in this case, there were no relevant signs to witness, and no enduring symptomatology. Accordingly, there was no possibility of correlating claimed symptoms with any meaningful clinical examination. It follows that the clinical experts were really in no better position than I was to assess matters of individual credibility and reliability, especially in a medico-legal (as distinct from a purely clinical) context. With respect to them, it might well be said that I was in a somewhat better position inasmuch as the Test Claimants’ accounts were thoroughly tested in the crucible of the forensic process. I do not propose to ignore the Claimants’ experts’ generally favourable impressions; the weight to be accorded to them should, however, be moderate.”
EXPERTS TRYING TO DETERMINE FACTUAL ISSUES
In Garcia -v- Associated Newspapers  EWHC 3137 Dingemans J considered the evidence of an expert.
“Dr Gerada gave evidence about which respective version of events was most likely to be reliable. I have not taken that evidence into account, and Mr Browne was justified in stating that Dr Gerada’s evidence on this point was not permissible expert evidence as it dealt with issues of fact, and not issues on which expert evidence was relevant.”
EXPERTS: DON’T GET ON THE STAGE
Mr Justice Coulson in Stagecoach Great Western Trains -v- Hind & Steel  EWHC 1891 (TCC) was highly critical of the expert called by the claimant.
“Save in exceptional circumstances, experts should not embark on this kind of fact-finding exercise, particularly when they perform it so unprofessionally. Matters of fact are for witnesses of fact, not for experts.”
MOST DEFINITELY NOT THE EXPERT’S JOB TO SUGGEST WHO SHOULD BE BELIEVED AND WHY
In Walls -v- London Eastern  EWHC 4724 (QB) Mr N Wilkinson, sitting as a judge of the High Court, stated:
“Mr Coomb seemed unused to the proceedings of the trial, despite his apparent experience of giving evidence, and chose the witness box as an opportunity to present a series of lectures. A question was an opportunity for him to hold forth on his particular theory, which was unreservedly supportive of the claimant’s case. He adopted the role of advocate, and despite having noted that he had been misled by Mr Walls, he put him forward as a genuine man. He told me that the claimant was dyslexic and that such people are often inaccurate. The adopted the claimant’s own adjective that he was “pigheaded”, and referred to the need for the claimant to pay his mortgage as the reason for his return to work. There is no evidence that the claimant is dyslexic. He labelled himself as such in re-examination. It is no part of an orthopaedic expert’s speciality to suggest who should be believed and why, and in this and many other respects Mr Coombs let himself down and diminished the role of the medical expert.”
- Over eager experts just do not help: they hunder and harm the cases of those who call them.
- More on experts: non-compliance with the rules taints the evidence badly.
- The credibility of witnesses: joint meeting and overreaching experts
- Evidence, experts and arson: analysing the evidence when serious allegations are made
- Principles of mitigation of loss and the credibility of expert witnesses
- Expert evidence: the expert’s role; seeing the wood for the trees
- Cross-examining expert witnesses: hints, tips and links.
- Beware the expert who lectures the court and tells the judge who to believe