A recent decision of the Court of Appeal in England & Wales has re-enforced the importance of full and frank disclosure on the part of expert witnesses. In EXP v Barker [2017] EWCA CIV 63 (“Barker”) particular emphasis was placed on the expert overriding duty to the court.

1. Hearing

During the hearing the defendant, a Consultant Neuroradiologist, relied on the expert evidence of a former colleague. This was not disclosed to the court by the expert or the defendant. The fact of and the depth of their past professional relationship only came to light during cross examination. There was also a concern that steps had been taken to conceal their former professional relationship.

2. Appeal

The Court of Appeal considered the original decision. They found that the judge had considered that the expert witness “had so compromised his approach that the decision to admit his evidence was finely balanced, and that the weight to be accorded to his views must be considerably diminished”. It was found on appeal that the judge was fully entitled to take that view. The Court of Appeal went further stating that had he fully excluded the expert’s evidence entirely it would have been a proper decision.

They considered the fact that “Our adversarial system depends heavily on the independence of expert witnesses, on the primacy of their duty to the Court over any other loyalty or obligation, and on the rigour with which experts make known any associations or loyalties which might give rise to a conflict”.

3. Disclosure

The Court of Appeal found that the expert witness had failed to disclose his relationship with the Defendant, despite an express direction to do so. He had in fact taught, mentored and co authored papers with the defendant. Indeed, the omission of any mention of papers co-authored with Dr Barker was a matter of serious concern.

4. Rejection of Evidence

Furthermore, the Court of Appeal found that there was good reason for doubting Dr Molyneux’s approach to the problem in hand. Dr Molyneux knew that the defendant’s second expert, Mr Byrne, was relying on research which was highly criticised. Dr Byrne provided a report to the defendant but was ultimately not called to give evidence. He referred in his report to a study the ISUIA (an international study on unruptured intracranial aneurysms investigators) had carried out. This paper had been severely criticised internationally with suggestions of poor methodology and systemic bias in the selection of patients. The Journal of Neurosurgery stated that the study had been “severely compromised”.

Dr Molyneux was a committee member of the ISUIA. As the judge observed, Dr Molyneux knew the study had been inaccurately described by Mr Byrne, and knew that evidence might well be given which, as the judge described it, “was seriously deficient and misleading“. Moreover, the Court of Appeal considered that it was an inadequate explanation from Dr Molyneux to say this arose from the neurosurgical evidence, and was no business of his. Due to the controversial nature of the paper, and Dr Molyneux’s position in the organisation associated with the research, it was entirely possible that he might himself have been cross examined about it.

In fact they further considered that a scrupulous expert in Dr Molyneux’s position should be pointing out the problem to the legal team well ahead of trial. In many instances, a court will be cautious in drawing inferences for that reason. However, on the facts of this case, the judge found that Dr Molyneux “did nothing“.

The Court of Appeal were of the view that it was clear that the judge simply did not feel able to rely on Dr Molyneux’s evidence as establishing that a responsible body of neuroradiologists would have failed to refer the respondent. The first instance judge had no obligation to do so. The judge had a considerable body of evidence, firmly expressed by those with proper expertise to support his finding. The original judge rejected Dr Molyneux’s evidence on both key issues. Having considered the facts of this case the Court of Appeal found that he was fully entitled to do so. The appeal was dismissed.

5. Consideration

While the test for admissibility of expert witness differs from jurisdiction to jurisdiction, judges in all jurisdictions including Ireland face the responsibility of weighing up expert evidence and coming to a determination with regards to its probative value. This case highlights the dangers of non-disclosure of any prior professional relationship with the respondent or defendant. There are many factors that the court will look at to assess the expert evidence that is presented to them. Central to this assessment is an experts’ objectivity. Courts expect experts to give their evidence from an objective and unbiased standpoint. Expert witnesses owe an overriding duty to the court above any consideration of their instructing party.

On a basic level the practicalities of our adversarial system mean that all evidence is selective and an expert can be chosen on the basis of whether they will help the party to win rather than on the basis of whether they will help the court to find the facts correctly. This is obviously divergent to the duty owed to the court by expert witnesses.

In January 2017 The Law Reform Commission’s released a Report on Consolidation and Reform of Aspects of the Law of Evidence (the “Report”). Part of the report deals specifically with expert evidence in Ireland. The Report considers numerous aspects of the law of evidence and makes final recommendations for their reform, as well as recommending the consolidation of the existing Evidence Acts.

To avoid these risks, the Commission’s Report recommends that the following duties should be set out in legislation whether giving evidence in a civil or criminal case:

  • an overriding duty to the court to provide truthful, independent and impartial expert evidence;
  • a duty to state the facts and assumptions (and, where relevant, any underlying scientific methodology) on which his or her evidence is based and to fully inform himself or herself of any fact that could detract from his or her evidence;
  • a duty to confine his or her evidence to matters within the scope of his or her expertise; and
  • a duty to his or her instructing party to act with due care, skill and diligence, including a duty to take reasonable care in drafting any written report.

Similar to the logic displayed in Barker there is an emphasis on the importance of independence and impartiality. Furthermore, the Report recommends that if an expert fails to comply with these duties a court may rule inadmissible his or her evidence.

The Report interestingly goes further in that it also recommends that an expert’s immunity from suit should be abolished. It recommends that it should be replaced by a statutory provision that an expert should be capable of being sued only if the evidence is given in a grossly negligent manner that is, falling far below the standard of care to be expected from that expert.

The Report also recommends that the Minister for Justice and Equality should publish statutory codes of practice for expert witnesses, prepared by a representative group of persons with suitable knowledge of the relevant areas; and that expert witnesses would be required to comply with the contents of such a code of practice. Developments in this area will be watched with interest.

The Barker decision can be accessed here.

The Law Reform Commission paper can be accessed here.