This article was produced by Nabarro LLP, which joined CMS on 1 May 2017.
A recent case has reminded us how crucial it is for an expert whose evidence is relied on in proceedings to be impartial, and for any conflict of interest to be declared at the outset, or as soon as it arises (see EXP v Barker [2015] 1289 QB).
The facts of the case relate to a clinical negligence matter, but the principles discussed in relation to experts’ duties are of wider application.
An expert’s duties are set out in Part 35 of the Civil Procedure Rules (CPR), in addition to which an expert is expected to have regard to the guidance contained in “The Civil Justice Council Guidance for the instruction of experts in civil claims 2014”.
An expert’s duties include the following:
- The duty to help the court on matters within their expertise. This duty overrides any obligation to the person from whom experts have received instructions or by whom they are paid (CPR 35.3).
- The expert’s evidence must be, and must be seen to be, the independent product of the expert, not influenced by the demands of litigation. A useful test is whether the expert would reach the same conclusion if he was given the same instructions by another party.
- The expert should take into account all material facts, including those facts which detract from the expert’s position.
- The expert should make it clear where an issue or question falls outside the expert’s expertise and where the expert is not able to reach a definitive conclusion (e.g. because there is insufficient information).
- The expert should not assume the role of an advocate, and neither should the expert promote the point of view of the party instructing him.
- The expert should inform his instructing party of any change of opinion on any material matter and the reasons for it as soon as possible. Such a change of opinion may have to be disclosed to the other party and the court.
The claimant in this case was a barrister who suffered neck and back injuries as a result of a road traffic accident in 1991. She suffered a relapse in 1997 and in 1999 was admitted to hospital because of a problem with her vision. The claimant visited her GP so that the problem with her vision and her longstanding neck and back pain could be further investigated. The claimant was referred to a consultant orthopaedic surgeon and underwent MRI scans, including a brain scan, the results of which she was told were “entirely normal”.
On 8 September 2011, 11 years after the MRI scans were carried out, the claimant collapsed unconscious at home as a result of an aneurysm on her brain that had ruptured. The claimant was admitted to hospital and underwent emergency surgery, but was ultimately left with a range of disabilities. The claimant attended an outpatient’s appointment in December 1999 and was seen by Mr Duffill, the consultant neurosurgeon who operated on her when she was admitted to hospital. The claimant brought with her to the appointment copies of the images from the 1999 MRI brain scan, which Mr Duffill looked at. Mr Duffill believed that the aneurysm that had ruptured could be identified on these images.
The claimant therefore brought these proceedings against the defendant alleging that the defendant negligently failed to identify and report the presence of the aneurysm following his analysis of the MRI brain scan carried out in 1999. This issue was the subject of expert evidence at the trial.
During the trial, it transpired that the defendant had worked at the same hospital as the defendant’s expert. In fact, the defendant’s expert had been a mentor to the defendant and had trained the defendant; they had worked together closely over a substantial period. This cast doubt on the defendant’s expert’s independence and the judge stated that his “independence and objectivity [had] been very substantially undermined”, consequently preferring the evidence of the claimant’s expert.
The judge said that he was inclined to rule that the defendant’s expert’s evidence was inadmissible because he could not be certain of its impartiality and objectivity, but the evidence was allowed as not to allow it would have been detrimental to the defendant.
