Civil Procedure Rule 35.1 provides that expert evidence ‘shall be restricted to that which is reasonably required to resolve the proceedings’. The underlying policy objective of this rule is to reduce the inappropriate use of experts to bolster cases.

The burden of proof in relation to the requirement for expert evidence lies with the party seeking permission to adduce it (JP Morgan Chase Bank v Springwell Navigation Corporation [2006] EWHC 2755 (Comm)). In the recent case of Wattret v Thomas Sands Consulting Ltd [2015] EWHC 3455 (TCC) the Technology and Construction Court considered the question of whether expert evidence should be permitted.

The claimants had engaged the defendant chartered quantity surveyors (who also had expertise in dispute resolution) to act on its behalf in respect of a dispute with its builder which had been referred to arbitration. However, an arbitral award was made against the claimants. The claimants then commenced proceedings against the defendant for breach of contract and tort in relation to the professional services it provided in the arbitration.

Numerous allegations were made against the defendant, including the defendant’s failure to adequately assess the risk of the claimant losing the arbitration; its failure to appreciate the problems with the claim; and its failure to advise the claimant to obtain after-the-event insurance. The defendant denied all the allegations.

The parties were unable to agree on whether expert evidence would be required. The defendant submitted that expert evidence should be given by a quantity surveyor with expertise in dispute resolution. Referring to Pantelli Associates Ltd v Corporate City Developers No 2 Ltd [2010] EWHC 3189 (TCC), the defendant argued it was standard practice that an allegation of professional negligence must be supported by a relevant professional with the necessary expertise.

Although not an absolute rule, the defendant explained that there would need to be a compelling reason for departing from it (see Sansom v Metcalfe Hambleton [1998] PNLR 542 at 549). Further, it was submitted that the claim was not akin to a solicitors’ negligence claim, and that solicitors and quantity surveyors acting as advocates were regulated by different codes of conduct and have completely different training. For this reason the case of Bown v Gould & Swayne [1996] 1 PNLR 130 should be distinguished; that was a case where the issue was one of law not practice.

The claimants drew the judge’s attention to British Airways plc v Spencer [2015] EWHC 2477 (Ch), a recent case on the admissibility of expert evidence, and submitted, inter alia, that on the facts of the present case, there ought to be no difference in principle between the standards of a solicitor on the one hand and a quantity surveyor experienced in dispute services on the other. On that basis it was said that the court should be able to determine the case without expert evidence.

However, if there was a theoretical distinction between the two standards, it was incumbent on the defendant to identify the practical distinctions on the facts of this case. The claimants also contended that if the court allowed expert evidence then it was crucial that it was narrowed down to what was strictly required.

The judge found that expert evidence was necessary. There was longstanding authority which is applicable to professional negligence cases (see, for example, Sansom v Metcalfe Hambleton above). However, the rule that expert evidence would be required in professional negligence cases was not an absolute rule, as confirmed by Butler-Sloss J in Sansom. One example in which expert evidence was not required is if the answer was obvious.

The judge took an example from the decision in Bown v Gould & Swayne. In that case the Court of Appeal applied the earlier judgment of Oliver J in Midland Bank Trust Company Ltd v Hett, Stubbs & Kemp [1979] 1 Ch 384 in which Simon Brown LJ said: ‘Mr Pearce-Higgins submitted that what the solicitors should have done is a matter of practice such as falls into the category of evidence that is properly the subject of admissible expert evidence within Oliver J’s formulation in Midland Bank.

That, however, in my judgment, is a fundamental misconception and it underlay all his submissions on the point. What solicitors should properly do in the very particular and highly individualistic circumstances of this case is by no means a matter of practice. It is a matter of law to be resolved by the judge.

‘Each of the seven respects in which the appellant’s solicitor’s first affidavit sought to contend that expert evidence would assist the court, proves, on analysis, to involve either a question of law or a question of fact. None of those matters can sensibly be regarded as inviting a view as to “some practice in [the solicitors’] profession, some accepted standard of conduct … laid down … or sanctioned by common usage”.

‘I entirely share the view of the judge below that, on the contrary, the evidence here sought to be adduced falls foul of Oliver J’s dictum. It would amount to no more than an expression of opinion by the expert, either as to what he himself would have done, which could not assist, or as to what he thinks should have been done, which would have been the very issue for the judge to determine.’

The judge made clear that the exception of Bown did not apply to the present case. This was not a solicitors’ negligence case; it was a claim against a firm of quantity surveyors. Therefore, it would be necessary to judge the defendant solely by the standard of a reasonably competent quantity surveyor providing dispute resolution services. The judge also noted that, on the facts of the case, he could see that there may be instances where there may be differences between what a legal practitioner would do or say in a given situation and what a quantity surveyor might do or say.

For example, in relation to the ATE insurance issue raised by the claimants, it may be that a reasonably competent quantity surveyor engaged in dispute resolution would be less well-versed in that type of funding than a solicitor.

The judge did, however, agree with the claimants’ contention that expert evidence should be restricted to what was relevant.

The judge expressed his concerns regarding unrestricted control of expert evidence when he stated: ‘… if unrestrained, there is a real risk that experts will provide swathes of commentary on each communication passing between the parties, giving their own slant or interpretation of what happened and what ought or ought not to have been advised… That must not happen in this case. If evidence of that sort is provided, the court will be able to make adverse orders for costs, even on an indemnity basis, against the party seeking to rely on such evidence [emphasis added].’

To control the provision of expert evidence, the judge ordered that the defendant provide a list of issues by reference to the pleadings which the claimants would be able to respond to. The parties would then agree the list which would then form the agenda upon which the experts were to provide evidence.

Two issues should be noted from Wattret. The first is that although expert evidence may be required in professional negligence disputes, it is not an absolute rule and the courts will determine the issue on the facts before it. Second, care must be taken when adducing expert evidence to ensure that it relates to issues which are relevant to the dispute and which will assist the court.

As the judge in Wattret made clear, a failure to control expert evidence will result in the court making adverse costs orders (possibly on an indemnity basis) against the party seeking to rely on such evidence.

Masood Ahmed is also a member of the Civil Procedure Rule Committee