Expert evidence is often talked of in terms of parties’ ‘rights’, i.e. to a fair trial or for equality of arms. In the field of PI and Clinical Negligence, it is taken for granted that except in the clearest of cases, the Court will admit (often gratefully) expert opinion on condition and prognosis as well as liability and causation. However, two recent decisions in different divisions of the High Court are a reminder that the Court’s powers under Part 35 are framed in terms of the power to restrict rather than permit, the use of experts.
CPR 35.1 ("Duty to restrict expert evidence") provides:
"Expert evidence shall be restricted to that which is reasonably required to resolve the proceedings."
The White Book notes (at paragraph 35.1.1) that the underlying objective is to reduce the inappropriate use of expert evidence.
The courts have taken an increasingly strict line on this, particularly following the changes to civil procedure ushered in by LASPO 2012 (the so called ‘Jackson reforms’). In Andrew Mitchell MP v News Group Newspapers Limited  EWHC 3590 (QB) for instance, Warby J considered whether it would be appropriate to admit expert evidence:
"CPR 35.1 imposes a duty on the court to restrict expert evidence to that which is reasonably required. I do not, however, read this as imposing a test of absolute necessity. A judgment has to be made in the individual case, and it has to be made before the evidence is heard and evaluated. My conclusion was that evidence which it is credibly said could conclusively determine the single most important issue in the case meets the criterion in the rule."
British Airways Plc v Spencer and (and ors)  EWHC 2477 (Ch)
In British Airways Plc v Spencer and 11 others (present trustees of the British Airways Pension Scheme) EWHC 2477 (Ch), the Deputy Master refused BA permission to rely on expert evidence. He held that‘various points raised in the pleadings’ on which BA suggested expert evidence would assist were, in fact,‘eminently capable of being determined by the judge at trial as issues of fact and law without the assistance of expert evidence...’. BA appealed. The appeal succeeded in part. Warren J encouraged courts to consider applications to rely on expert evidence in the following way:
- Whether, looking at each issue, expert evidence is necessary to resolve it. If it is necessary (not just helpful), it must be admitted.
- If the evidence is not necessary, whether it would assist the court in resolving the issue. If it would be of assistance, but not necessary, the court could determine the issue without it.
- Whether (in circumstances where the evidence would be of assistance but not necessary), in the context of the proceedings as a whole, expert evidence on that issue is reasonably required to resolve the proceedings (taking account of factors such as the value of the claim, the likely impact of the judgment, where the costs will fall, and the possible impact on the conduct of the trial).
Although the decision was fact sensitive, the court identified the following points in favour of allowing expert evidence:
The ‘very large’ financial implications of the decision for BA meant that it should be entitled to advance its best case.
- It would be undesirable to ’tie the hands of’ the trial judge.
- If the trial judge concluded that expert evidence would not assist, then he could decline to receive that evidence.
- The fact that BA would bear the costs of the expert evidence whatever happened, and that the trustees would bear no financial risk.
The full judgment is available at http://www.bailii.org/ew/cases/EWHC/Ch/2015/2477.html