A recent High Court decision underlines the burden on a litigating party and its expert witness to state frankly, and with sufficient detail, the nature and extent of any connection that could affect the expert’s independence: EXP v Dr Charles Simon Barker [2015] EWHC 1289 (QB).

The court rejected a suggestion that information disclosed in the CVs of the defendant and his expert witness in this case should have put the claimant on notice of a connection between them, which she ought to have pursued. The burden to disclose was fairly and squarely on the defendant and his expert witness; the claimant should not be expected to engage in “time consuming detective work” to try to ascertain the full picture bearing on the expert’s independence.

Where questions are raised about an expert’s independence, the court’s ultimate sanction is to rule that the evidence is inadmissible. However, even if the court concludes that it can fairly admit the evidence, any doubts about the expert’s independence and objectivity may affect the weight the court attaches to it. In either case, the implications for the party putting forward the evidence may be very serious indeed. The message for litigating parties, and expert witnesses, is that any issues should be disclosed fully and frankly at an early stage.

Rachel Lidgate and Ramyaa Veerabathran, a senior associate and graduate solicitor (India) in our disputes team in London, consider the decision below.

Background

The claimant brought a clinical negligence claim against the defendant, a consultant radiologist, alleging that he had negligently failed to spot an aneurysm on an MRI of her brain in 1999. The expert evidence was obviously crucial to the adjudication of the claim.

The defendant’s CV, which was attached to his witness statement, indicated that he had been a senior registrar in the Department of Neuroradiology, Radcliffe Infirmary, Oxford. The expert’s CV showed that he had been, in the same period, a consultant neuroradiologist at the Radcliffe Infirmary. During cross examination at trial, it emerged that the defendant and the expert witness had shared a longstanding connection – the defendant had been trained by the expert and they had worked closely together over a substantial period. They had also collaborated on academic publications and had served together as officers of the British Society of Radiologists. It was further revealed that it was the defendant who had specifically proposed that this expert be requested to give evidence for the defence.

Decision

After considerable reflection, the judge (Kenneth Parker J) concluded that the evidence could be fairly admitted, but warned that he must “bear powerfully in mind” the reservations he retained about the expert’s independence in assessing the weight he should give to his evidence.

Onus to disclose interest

The defendant submitted that the CVs provided by the defendant and his expert witness had effectively put the claimant on notice of a potential connection and that the onus was on the claimant to pursue the matter. Rejecting this submission, the court held that the burden to disclose the nature and extent of any connection was entirely on the defendant and, in particular, on the expert witness in question, who owed an overriding duty to the court. In this case, the court held, there had been a very substantial failure, both on the part of the defence and specifically on the part of the expert, to disclosure with adequate particularity the nature and extent of the connection so that the court would have a complete understanding of all matters that could realistically affect the expert’s independence. Parker J noted that this default had occurred despite the Master’s direction that experts should incorporate in their reports details of any employment or activity that raised a possible conflict of interest.

The court noted that failure to make early disclosure, particularly of an obvious conflict, would tend to raise a natural suspicion that the default was not inadvertent and reinforce a concern that the witness’ independence was so compromised that his/her evidence must be entirely inadmissible.

Factors casting doubt on independence

The judge identified two factors that particularly called into question the expert’s independence:

The expert had referred to the defendant by his first name at one point in his oral evidence. This tended to indicate that at least traces of the bond between the defendant and his expert witness were still apparent and that the expert witness did not have the requisite degree of professional objectivity about the defendant. The expert had failed to point out a seriously misleading reference to a discredited academic study that was relied upon in the evidence of another of the defendant’s experts.

Legal principles applied

The court noted that the principles applicable to the admissibility of expert evidence had been analysed and summarised with “admirable lucidity” in Phipson on Evidence at [33-29]:

It is always desirable that an expert should have no actual or apparent interest in the outcome of the proceedings. The existence of such an interest … does not automatically render the evidence of the proposed expert inadmissible. It is the nature and extent of the interest or connection which matters…. Where the expert has an interest of one kind or another in the outcome of the case, the question of whether he should be permitted to give evidence should be determined as soon as possible in the course of case management. The decision as to whether an expert should be permitted to give evidence in such circumstances is a matter of fact and degree. The test of apparent bias is not relevant…. The questions which have to be determined are whether: the person has relevant expertise; and he is aware of his primary duty to the Court…, and … willing and able, despite the interest or connection with the litigation or a party thereto, to carry out that duty. The judge will have to weigh the alternative choices open if the expert’s evidence is excluded, having regard to the overriding objective of the Civil Procedure Rules. If the expert has an interest which is not sufficient to preclude him from giving evidence the interest may nevertheless affect the weight of his evidence.

Even where the court decides to permit an expert to be called where his independence has been put in issue, the expert may still be cross-examined as to his independence and objectivity.

Admissibility

Parker J stated that he had very nearly ruled that the evidence in question was not admissible. However, he ultimately concluded that he could fairly admit the evidence. Two factors appear to have been significant: non-admission would have been fatal to the defendant’s case; and there was no doubt about the expert’s expertise and competence to assist the court on the central issue in the case. Although the judge ultimately decided to admit the evidence, he observed that his reservations about the expert’s independence would be taken into account in assessing its weight.

In analysing the evidence before it, the court observed that the core issue in this case turned on the court’s evaluation of the competing, finely balanced medical judgments of experts supporting either party, which in turn was significantly influenced by its confidence in their impartiality. The judge noted that he had complete confidence in the objectivity of the claimant’s expert witness. On the other hand, his confidence in the defendant’s expert witness had been seriously undermined by the failure to disclose the potential conflict of interest. Therefore, the judge preferred to accept the judgment of the claimant’s expert witness.