Bryan Patterson-Whitaker considers the price to be paid for changing experts in the course of litigation.
5 October 2016

Bryan Patterson-Whitaker considers the price to be paid for changing experts in the course of litigation.

Allen Tod Architecture (In Liquidation) v Capita Property & Infrastructure Ltd (previously Capita Symons Ltd) [2016] EWHC 2171 (TCC)

Bryan Patterson-Whitaker considers the price to be paid for changing experts in the course of litigation.

The High Court (TCC) has once again considered the complex issue of when a party may be permitted to change experts and what conditions, if any, may be imposed.

The claimant was an architect engaged by Barnsley MDC to provide a ‘one-stop shop construction management service’ in a project to renovate the town’s Civic Hall in 2006. It in turn retained the defendant to provide structural engineering advice and other services. The project hit very serious problems in mid-2007 when structural deficiencies were encountered in the walls of the building. Barnsley MDC brought a claim in professional negligence against the claimant which was settled in mediation. The claimant issued professional negligence proceedings against the defendant.

The claimant came to instruct expert A in September 2014 but there were extensive delays in his work. After 18 months the claimant lost confidence, having never received a final report. A new expert B was therefore instructed in April 2016 and just before the pre-trial review.

The directions in the case gave the parties permission to adduce expert opinion by reference to discipline, rather than by named experts. Whilst this meant that the claimant did not need permission to change experts, the order also made clear that a party seeking to call oral evidence had to apply for permission to do so – see CPR 35.4. The court noted the express power under CPR 3.1(3)(a) to make any order subject to conditions. It was the defendant’s application that such permission should be conditional upon disclosure of the letters of instruction for experts A and B (subsequently provided voluntarily) and, more controversially, disclosure of any report, document, note or correspondence in which the substance of expert A’s opinion was set out. The claimant argued that the outstanding documents were privileged and should not be subject to an order for disclosure. It also argued that it had already disclosed sufficient material and had not been ‘expert shopping’.

The Court undertook a detailed review of the authorities and derived the following principles:-

(a) the court had a wide and general power under the CPR to exercise its discretion whether to impose terms when granting permission to a party to adduce expert opinion evidence;

(b) the court could give permission for a party to rely on a replacement expert, but such discretion was usually exercised on condition that the report of the original expert was disclosed. The party seeking permission would therefore have to waive privilege in the first expert's report – Vasiliou v Hajigeorgiou [2005] EWCA Civ 236;

(c) once the parties had engaged in a relevant pre-action protocol process, and an expert had prepared a report in the context of such process, that expert owed a duty to the court irrespective of his instruction by one of the parties. Accordingly, there was no justification for not disclosing such a report – Edwards-Tubb v JD Wetherspoon Plc [2011] EWCA Civ 136;

(d) the court's power to impose a condition for the disclosure of the first expert's report arose irrespective of the occurrence of any "expert shopping". It was a power to be exercised reasonably on a case-by-case basis, having regard to all the circumstances – BMG (Mansfield) Ltd v Galliford Try Construction Ltd [2013] EWHC 3183 (TCC); and

(e) the court would require strong evidence of expert shopping before imposing a term that a party disclose documents other than the report of the first expert (such as attendance notes and memoranda made by a party's solicitor of discussions with the expert) as a condition of giving permission to rely on a second expert – BMG applied again.

As a general rule, the Court also considered there to be no difference of substance between the disclosure of a ‘final’ Part 35 compliant expert report and any other ‘draft’ or ‘provisional’ report. Indeed, any document where expert A had set out the substance of his opinion was susceptible to disclosure.

On the facts, although the instant case was not one of obvious ‘expert shopping’, the Court would still direct disclosure of any material produced by expert A, in which he expressed his opinion on the issues in the case.  

The claimant’s application for permission to call expert B was therefore granted but subject to the extensive disclosure demanded by the defendant.


Practitioners in the field will be aware of the need to exercise extreme caution in the selection of experts. It is increasingly apparent that once a particular individual has been chosen, their opinion (good or bad) is likely to emerge in evidence.

When it comes to expert opinion, the old adage of ‘buy well, buy once’ has a very modern application.



Bryan Patterson-Whitaker

2nd October 2016