When is expert evidence 'reasonably required' under rule 35.1? (BA v Spencer)
The Chancery Division has allowed British Airways' (BA) appeal [British Airways plc v Spencer and others (trustees of the Airways pensions scheme)  EWHC 2477 (Ch),  All ER (D) 101 (Aug)] against a deputy master's case management decision refusing BA permission to call or rely on expert evidence. In doing so, it carefully considered the meaning and purpose of rule 35.1 of the CPR. It also set out the test to be applied by a court in deciding whether a party should be allowed to adduce expert evidence by reference to that evidence being reasonably required or of assistance to the court in resolving a particular issue in the case or the proceedings as a whole. This judgment also looked at rule 3.1(2)(k) and the extent to which case management decisions bind the trial judge.
Practical implications arising from this judgment include:
- where the court might be helped by an explanation of matters or procedures, parties should seek to present the court with an agreed explanation rather than seek to admit professional opinions on these (para )
- when deciding whether to grant permission to adduce expert evidence, the court must consider each pleaded issue in turn, even where there is some likelihood some of those issues may fall away during the course of the proceedings. The only time a pleaded issue does not need to be considered in this regard is where it is no longer 'in issue' or dispute (eg where the court has excluded any particular issue(s) from consideration under CPR 3.1(2)(k))
- where seeking permission to adduce expert evidence--and particularly where you consider the court may not be persuaded such evidence is reasonably required to resolve the particular issue--you should seek to satisfy the court that:
- the evidence would assist the court in resolving the particular issue(s) and, more generally, the proceedings as a whole
- a party who is not permitted to adduce the evidence sought may be prevented from presenting the case they wish. Here, the Chancery Division recognised the capacity of case management decisions to 'tie the hands of the trial judge', particularly in relation to evidence where, in fact, 'the trial judge will be in the best position to assess whether or not evidence should be admitted'. Although recognising this as 'an inherent part of our system', Warren J observed directions which have such an effect 'must be viewed with great caution'. Practitioners may also, where appropriate, wish to respectfully remind the court of the relatively limited scope of appealing case management decisions.
- think carefully about the issues you are seeking permission for. Here, the court found expert evidence was not required where there was:
'an objection in principle...because the advice was directed to the Trustees who are not actuarial experts. I would hope and expect that the court would be able to understand--especially with the assistance of counsel--the advice which was given just as much as the Trustees' (para )
- avoid seeking to adduce expert evidence on issues which are actually matters of fact. For example, as here, the issues of what the trustees were advised and how they reacted to that advice. The court drew the distinction acknowledging that, were the contention to be the trustees knew the advice to be wrong, expert evidence may be of assistance (para ).
- where you suspect the expert evidence your opponent seeks to adduce may, ultimately, be unnecessary for whatever reason, consider seeking an appropriate costs be included within the directions order granting permission for this expert evidence
- should any issues fall away in the course of the proceedings, consider the effect of this on any expert evidence. This is particularly so where the expert evidence was allowed as being necessary to resolve that particular issue but where it may not necessarily assist in resolving the proceedings as a whole (see last bullet below)
This claim about BA's pensions schemes was complex and involved a large number of pleaded issues as well as there being a large amount of money at stake for the claimants.
The deputy master, having found no expert evidence was necessary, refused the claimant permission to adduce expert evidence. The claimant, BA, successfully appealed that case management decision.
In allowing the appeal, the Chancery Division considered the underlying policy objective of CPR 31.5 (namely restricting expert evidence to 'that which is reasonably required to resolve the proceedings') as being to 'reduce the incidence of inappropriate use of experts to bolster cases' and referred to what Aikens J said in JP Morgan Chase v Springwell  EWHC 2755 (Comm),  All ER (D) 44 (Nov) in this regard.
In determining the extent to which BA would be entitled to adduce expert evidence, the Chancery Division considered each of the pleaded issues, applying the test set out below.
Factors the court took into account included:
- the very large sums of money that turned on the outcome of the case for the claimant: 'Provided that this does not result in oppression or other unfairness to the Trustees, or to a disproportionate allocation of court time, BA should be entitled to put its best case and adduce the evidence which it reasonably considers will advance that case' (para )
- the undesirability of tying the hands of the trial judge 'if that can sensibly be avoided'. The court suggested that, in some cases, and albeit subject to the proviso set out in the bulleted point above 'any doubt about the amount of assistance which the court might gain is best resolved in favour of...the person wishing to adduce it'
- the trial judge could decline to receive evidence they decided would not assist them
- the cost of the exercise would be borne by the claimant in any event irrespective of whether the evidence was actually adduced or relied on in court. As such, the respondents were at no financial risk
- the decision was not expected to result in wide-ranging instructions or lengthy expert reports
- the time estimate for trial was 'agreed on the footing that expert evidence would be adduced' and there had been no suggestion this would have to be revised were the claimant granted this appeal for permission
Note: this case was unusual in that the claimant would always be liable for both sides' costs of adducing expert evidence (see para ). As such, the Chancery Division considered 'recognition of the ultimate costs burden ought to have been a weighty factor in the exercise of the [deputy master's] discretion' (para ). It would have been interesting to see how the court would have balanced the factors above with its duty to further the overriding objective had the unusual costs circumstances not existed.
Summary of key findings
In granting the appeal, the Chancery Division found, among other things:
- although the court and the parties should have regard to the overriding objective, 'the court should not be over-zealous in excluding evidence in order to save time and cost' (para )
- just because expert evidence may be helpful on a particular issue, that is not to say it is automatically to be admitted where to do so would be disproportionate in the light of the overriding objective (para )
- a judgment as to admissibility of expert evidence:
'needs to be made in every case and, in making that judgment, it is relevant to consider whether, on the one hand, the evidence is necessary (in the sense that a decision cannot be made without it) or whether it is of very marginal relevance with the court being well able to decide the issues without it, in which case a balance has to be struck and the proportionality of its admission assessed. In striking that balance, the court should, in my judgment, be prepared to take into account disparate factors including the value of the claim, the effect of a judgment either way on the parties, who is to pay for the commissioning of the evidence on each side and the delay, if any, which the production of such evidence would entail (particularly delay which might result in the vacating of a trial date)' (para )
- the 'correct approach to the admissibility' of expert evidence is set out in paras  and , namely, by reference to each of the issues in the case:
- expert evidence which is necessary, rather than 'merely helpful', in order to resolve that particular issue must be admitted
- expert evidence which is not necessary, but which might assist the court in resolving that particular issue, may be admitted where it is reasonably required to resolve the proceedings as a whole. Evidence can be helpful even if it is not 'determinative of any issue' (considering Mitchell para )
- CPR 35.1 refers to 'the proceedings' which can, as in this case, contain a large number of pleaded issues. Although, ultimately, some of these may not need to be resolved, whether under the court's power to restrict the issues for determination under CPR 3.1(2)(k) or otherwise, unless and until issues have been excluded from consideration:
'it cannot be said...it will not be necessary to decide any particular pleaded issue in order to resolve the proceedings. It must follow that, if expert evidence is reasonably required to resolve a pleaded issue, it will also be reasonably required to resolve the proceedings. However, unless the evidence is necessary in order to resolve an issue, whether it should be admitted needs to be assessed in the context of the resolution of the proceedings as a whole. There would be nothing inconsistent in accepting that particular evidence ought to be admitted in resolving an issue within the proceedings if that issue stood alone but deciding, in the context of the proceedings as a whole, that such evidence was not reasonably required in resolving the proceedings (unless that evidence was necessary to resolve the issue).
Thus in Mitchell, the expert evidence was not necessary but it was, or might have turned out to be, helpful. Because the issue to which it went was central to the case and because the evidence might be conclusive, it was admitted. But if in another case a similar issue were to arise which, instead of being central, was merely peripheral, the court might take the view that the expert evidence was not reasonably required to resolve the proceedings. The balance could come down in favour of refusing to admit that evidence.'
- Court: Chancery Division (on appeal)
- Judge: Warren J
- Date of judgment: 21 August 2015