Are you entirely independent? The importance of disclosing who you know at the outset

In this article, Ann-Marie Christie, MAPS’ General Counsel, reviews the Court of Appeal decision in EXP v Barker [2017] EWCA Civ 63, where an expert’s credibility was called into question after failing to disclose a previous professional relationship with the defendant. The article highlights the importance of identifying and declaring conflicts of interest and revisits the duties placed on experts to act independently and disclose any potential conflicts at the earliest opportunity. A look at an expert’s duty relating to conflicts of interest and the decision in the Court of Appeal case of EXP v. Barker 2017 EWCA Civ 63 – here. The expert’s credibility was called into question after he had failed to disclose that he had been a colleague of the defendant.

Summary of the Facts

In this clinical negligence case, the expert giving evidence for the defendant failed to disclose that he and the defendant had been former colleagues and had worked closely together. The judge rejected the defendant’s expert evidence, primarily because of the expert’s failure to disclose this, although there were some other points the Judge found issue with. The decision was appealed by the defendant.   

You may read the facts of the case yourself, but the primary point to highlight from this case is what was said in the judgment about conflicts of interest.

Counsel for the claimant submitted that the judge should entirely exclude the evidence of the defendant’s expert and, in the original trial judgment, the judge summarised at paragraph 56 the following principles, which had been taken from Phipson on Evidence at paragraphs 32-29. They were:

1. It is always desirable that an expert should have no actual or apparent interest in the outcome of the proceedings.
   
2. The existence of such an interest, whether as an employee of one of the parties or otherwise, does not automatically render the evidence of the proposed expert inadmissible. It is the nature and extent of the interest or connection which matters, not the mere fact of the interest or connection.
   
3. 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.
   
4. 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 to the question of whether an expert witness should be permitted to give evidence.
   
5. The questions which have to be determined are whether:
   • the person has relevant expertise; and
   • they are aware of their primary duty to the court if they give expert evidence, and are willing and able, despite the interest or connection with the litigation or a party thereto, to carry out that duty.
     
6. 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.
   
7. If the expert has an interest which is not sufficient to preclude them from giving evidence, the interest may nevertheless affect the weight of their evidence.

Even where the court decides to permit an expert to give evidence after their independence has been called into question, the expert may still be cross-examined about their independence and objectivity.

At paragraph 57, Mr. Justice Parker states:

“The authorities emphasise the importance of disclosure, indeed early disclosure, of any conflict.”

The Guidance of the General Medical Council published on 25^th March 2013, with effect on 22^nd April 2013, entitled Acting as a witness in legal proceedings – here – also rightly emphasises the importance of early disclosure, as follows:

Conflict of Interest

If there is any possible conflict of interest – for example, you have been professionally or personally involved with one of the people involved in the case in the past, or you have a personal interest in the case – you must follow our guidance on conflicts of interest. You must also make sure the people instructing you, the other party and the judge are made aware of this without delay. You may continue to act as an expert witness only if the court decides the conflict of interest will not affect the case.

The sentence underlined was emphasised by the judge in his judgement.

For those who wish to read the latest GMC guidance, which came into effect on 30 January 2024 and was updated on 13 December 2024, it can be found here.

The appeal was unanimously rejected. Lord Justice Irwin said the starting point was to look at what the judge had decided: 

“He considered that the 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. In my view he was fully entitled to take that view.”

Experts should ensure they are familiar with Part 35 rules – here – and the CJC Guidance for the Instruction of Experts in Civil Claims – here.