Assessing expert evidence in court

February 1, 2016 geyre

What makes for a good expert in court? There are many components. But in the civil courts it is the judge who has to assess the expert evidence and who decides, where there is a disagreement, which expert’s evidence to prefer (on the balance of probabilities).

A leading exposition of the judge’s process in carrying out this task was given by Lord Justice Stuart-Smith in his judgment in Loveday v Renton[1] when he explained how “the court has to evaluate the witness and the soundness of [the expert] opinion.” No better and more complete explanation has been given since.

The judge identified a number of important factors which will be taken into account in deciding whether to accept or reject the expert’s evidence:

The reasons given by the expert for his or her opinions and the extent to which they are supported by the evidence.
The internal consistency and logic of the expert’s evidence.
The care with which the expert has considered the subject and presented the evidence.
The precision and accuracy of thought as demonstrated by the answers to questions.
The nature of the response to searching and informed cross-examination.
The extent to which the expert faces up to and accepts the logic of a proposition put in cross-examination or is prepared to concede points that are seen to be correct;
The extent to which an expert has conceived an opinion and is reluctant to re-examine it in the light of later evidence, or alternatively demonstrates a flexibility of mind which may involve changing or modifying opinions previously held.
Whether or not an expert is biased or lacks independence.
The expert’s demeanour in the witness box.

Experts are often surprised at this list, its length and particularly the idea that demeanour might play a role (along with inconsistency or an over-rigidity of thought). But as can be seen in court judgments again and again, between them these ‘tests’ will provide the judge with the ability to explain, sometimes in rather robust language, why one expert’s opinion has been rejected.

To avoid failing one of these ‘tests’, an expert must not only be sure of the grounds relied on to support an opinion, but must have carried out adequate preparation before giving evidence (including providing a well-structured report in the first instance). Further the expert will also benefit from understanding how cross-examination is structured and how to give a good and effective account of him or herself in the witness box.

It is not enough for the expert in court simply to rely on the belief that he or she is right!

[Who or what is medico-legal minder? Terms and conditions apply]

[1] [1990] 1 Med LR 117 at page 125

The naughty step – another expert criticised for not complying with his duty.

January 25, 2016February 1, 2016 geyre

Background: The previous blog referenced Rich v Hull and East Yorkshire Hospitals NHS Trust [2015] EWHC 3395. The judge was disappointed with aspects of one of the experts’ involvement in the case. The expert’s evidence when seeking to explain in cross-examination an inadequate answer to a question in the agenda for the joint meeting of experts was described by the judge as “disingenuous”, and his claim to have omitted words from another answer to a question at the joint meeting as “not [having] been satisfactorily explained”.

The judge’s finding: The judge referred to the expert’s obligations to the court as explained in The Ikarian Reefer[1] and concluded that the expert had not given “objective and independent evidence to the Court on a number of important matters”.

The judge’s sentence: The expert got off light. No referral to the GMC was made. Apart from the professional embarrassment consequent on the experience in court and the publication of the judgment, the judge directed that he should be sent copies of the judgment and the relevant extract from the White Book [a practitioner’s book containing the Civil Procedure Rules (“CPR”) and notes of explanation] which summarised the guidance in The Ikarian Reefer. With due respect to the judge, I would suggest that even more useful would be to send the expert a copy of Part 35 of the CPR, the Practice Direction to Part 35 and the Guidance for the Instruction of Experts in Civil Claims 2014, all of which the expert would expressly have claimed to have followed in the required statement in his report that he, like all experts –

(a) understands their duty to the court, and has complied with that duty; and

(b) is aware of the requirements of Part 35, this practice direction and the Guidance for the Instruction of Experts in Civil Claims 2014. (PD35 3.2(9))

He should also purchase a suitable guide or manual for the use of experts giving evidence in civil claims which sets out clearly their duties and obligations.

The good news: For the party that instructed the expert the good news was that the judge concluded that the breach of duty of the expert was not so serious as to oblige him to disregard his evidence altogether but he did take the breaches into account in evaluating the reliability of his evidence overall.

The moral: These days a professional offering his or her services as a court expert has no credible excuse for not understanding fully the duties and responsibilities of an expert and complying with them.

[Who or what is medico-legal minder? Terms and conditions apply]

[1] [1993] 2 Lloyd’s Rep 68