The expert witness has long been important in professional negligence cases but must be used with care, warns Edward Bartley Jones QC. Edward Bartley Jones QC is a barrister at Exchange Chambers in Liverpool.
The use of expert evidence is considered in almost all professional negligence cases, but there are often fundamental misconceptions regarding the functions and duties of experts and the admissibility of expert evidence in particular circumstances.
Experts can forget their functions and duties and at times lawyers fail to remind their experts of their role, or seek to adduce expert evidence in inappropriate or inadmissible circumstances. Understandably, this can lead to increasing judicial impatience.
An expert witness should provide independent assistance to the court by way of objective, unbiased opinion and should be confined to matters within his expertise. The expert should not assume the role of an advocate for the party retaining him. Nor should he slant (or be asked to slant) his opinion.
The expert is not a partisan. It follows that if an expert changes his view (especially after exchange of experts' reports) then this should be communicated to the other side without delay and, where appropriate, to the court.
Frequently the distinction is not made between material useful for submission or cross-examination and material which can be placed before the court as expert testimony.
Both sets of material are lumped together in one report doubly unfortunate when the expert appears to assume the role of an advocate for his side.
Often, in the past, such reports have been allowed into evidence but signs of judicial concern are increasing. In 1995 Mr Justice Waller concluded a case by urging legal advisers that guidance should be given to experts to the effect that their role was to be independent and not that of advocate, and that their evidence should be limited to matters of genuine expertise.
Problems can still arise as to the admissibility of a particular expert's report. Most practitioners will be familiar with the decision of the Court of Appeal in Bown v Gould & Swayne (1996) whereby it was held, in a solicitor's negligence case, that expert evidence from a solicitor was inadmissible. Considerable care must be taken here, however.
It is undoubtedly the case that expert testimony on the legal test to be applied (that is the nature and extent of the contractual or tortious duty owed) is inadmissible.
Expert evidence is not admissible on questions of law or questions of fact (if those questions of fact are capable of decision without the assistance of an expert). But expert evidence can be admissible on the issue whether the legal test has been breached, even if that question is the “ultimate” question in issue in the proceedings.
Thus an expert can, in the right circumstances, express his opinion on the issue of breach even if that question of breach is the very question which the court has to decide. This was established by Mr Justice Jacob in Routestone Limited v Minories Finance Limited (unreported) 16 May 1996.
Indeed, it may be vital for the expert to address the ultimate question which the court has to decide. It would appear, however, that in solicitors' negligence cases expert evidence on breach is not admissible, even if that is the ultimate question, since breach is a matter which the court itself can decide, without expert evidence, either on the basis of fact or law.
Further, it can be that expert evidence is admissible (in cases other than solicitors' negligence) to establish the primary factual matrix on which the court makes its decision as to the legal test to be applied.
This can be particularly so in medical negligence cases. It seems that the bald note in The White Book (38/4/2 at page 655) to the effect that in no case is it competent for an expert to express his opinion upon any of the issues (whether of fact or law) which the court has to determine, needs to be reconsidered in the light of Section 3 of The Civil Evidence Act 1972 and the decision of Mr Justice Jacob already referred to.
One area of potential development is the appointment by the court of its own court expert under Order 40. Over the years, appointments under Order 40 have been very few in number.
But there are now signs that the court will be more ready in appropriate cases to appoint a court expert. The Court of Appeal has recently (1996) approved the appointment of a court expert by one of the official referees. The Court of Appeal described this as a bold and innovative step and held that Order 40 was not confined to resolving questions of a scientific or technical nature.
Nor was Order 40 confined to subsidiary questions. It could be applied to the main issue in the case. Parties should, therefore, be aware of Order 40 and not be surprised if the court seeks to exercise its powers thereunder.
It is probably true to say that, over the years, expert evidence not complying with basic principles has been heard and admitted. There are clear signs of change reflected not only in judicial decision but also in the Interim (1995) and Final (1996) Woolf Report.
Litigators should beware.