A recent High Court decision shows that the court may order a party to disclose documents as a condition of granting permission to rely on an alternative expert, despite the original expert having been engaged at a very early stage outside the requirements of a formal pre-action protocol process: Rogerson (t/a Cottesmore Hotel, Golf and Country Club) v Eco Top Heat & Power Ltd [2021] EWHC 1807 (TCC).

It is well-established that the court can, and ordinarily will, require a party to waive privilege in a previous expert’s report as a condition of granting permission to adduce evidence from a different expert, and this power extends to experts instructed pre-issue as well as later in the proceedings (see for example Edwards-Tubb v J D Wetherspoon [2011] EWCA Civ 136 (considered here). It has, however, been unclear precisely how far back in time this jurisdiction can reach. The present case suggests that the early limit is the point when a process of engagement for the purposes of litigation has occurred, though there is no need for that to be part of a formal, pre-action protocol process.

In Edwards-Tubb the court commented that a waiver of privilege would not normally be required where an expert had been instructed to advise a party privately, at its own expense, rather than to prepare a report for the purposes of the proceedings. In the present case the court was satisfied that the expert had been instructed with a view to being appointed as expert for the purposes of the proceedings – drawing that inference in part because the relevant party had not been transparent as to the terms of the expert’s retainer. Even if that was wrong, and the expert was engaged only for private pre-litigation advice, the court considered that the features of the case were sufficiently unusual – including the level of pre-action engagement between the parties’ experts – that it was appropriate to require a waiver.

This case is a reminder that if parties wish to change experts, and need the indulgence of the court to be able to do so, they should assume that they may need to disclose any previous reports (or draft reports or other documents setting out the previous expert’s views) as the “price” of that indulgence. This will be particularly likely where there has already been a process of engagement between the experts for the purposes of the proceedings, whether or not the expert has been retained with a view to preparing a formal expert report for use in the proceedings. The present decision further illustrates that, when seeking the court’s permission for a new expert, being opaque as to the circumstances of the original expert’s instruction or the reasons for changing experts is unlikely to assist a party’s case.


The action arose from a fire in June 2018 at a hotel owned by the claimant. At the time of the fire, the defendant building contractor was carrying out window installation works at the hotel.

The parties appointed forensic fire investigators to establish the cause of the fire. The defendant’s investigator was Dr Nagalingam (“N”) who undertook two site visits in June 2018 and interviewed some of the claimant’s witnesses jointly with the experts appointed by the claimant and his insurer. At the end of the interview N reportedly agreed with the other experts that the fire was most likely caused by a cigarette. In October 2019 he discussed his views on causation with the defendant’s solicitors and these were recorded in an attendance note.

The claimant started proceedings in August 2020 for breach of contract and negligence seeking damages of £7,642,450. The claimant’s case was that the fire was most probably caused by a cigarette dropped by one of the defendant’s employees or by a spark from an angle grinder they had used. The defendant denied this and suggested that, if a cigarette caused the fire, it may have been discarded by the claimant’s own staff.

The defendant sent draft directions to the claimant, including that it should have permission under CPR 35.4 to call Ms Emma Wilson (“W”) as an expert concerning the cause of the fire. The claimant asked for an explanation for the change of expert but was not satisfied with the answers.

The claimant did not oppose the change of expert but applied for a condition to be imposed as the “price” of the permission that the defendant disclose various categories of privileged documents, including the attendance note taken by the defendant’s solicitors in October 2019. The claimant submitted the court had jurisdiction to make such an order even though N was instructed before the pre-action protocol for construction and engineering disputes had commenced. He submitted that there was a very strong inference of expert shopping, including because the defendant had failed to give transparent reasons for N’s original engagement and for subsequently instructing W.

The defendant countered that the court should not exercise its discretion to impose such a condition, as this was not a case of expert shopping. It was justified in changing its expert having regard to W’s greater experience in cigarette induced fires. Moreover, it argued that a clear distinction should be made between an expert (such as N) who was instructed in the immediate aftermath of an event for the purposes of taking private pre-protocol advice and one instructed once litigation is in prospect and the potential issues areknown about. Here the pre-action protocol process had not even begun when N was instructed, the litigation was still at a very early stage and the interests of justice would not be impacted by calling W in place of N.


The High Court (Mr Alexander Nissen QC sitting as a High Court Judge)granted the claimant’s application to impose a condition on the grant of permission for a new expert.

He noted that it was clear that the court had power to impose the condition sought even if it meant disclosing privileged documents. This did not directly override privilege but presented the party with a choice in which the “price” for permission to rely on a new expert was a waiver of privilege in relation to the original expert.

In the present case, the judge addressed two related considerations as to whether the court should exercise its discretion:

(i) Was the nature and timing of N’s early instruction as expert such that the decision to rely on W in his place was not tantamount to a change of expert at all?

The judge noted that it was clear that the jurisdiction to make an order imposing a condition of the type sought by the claimant can attach to privileged reports or opinions generated before as well as after the issue of proceedings. However, absent some unusual factor, the same justification for hedging privilege does not arise where an expert is consulted at the pre-protocol stage to advise privately at the expense of the party instructing him.

The judge noted that in Edwards-Tubb, a case subject to the Personal Injury Pre-action Protocol, the Court of Appeal held that documents created at the stage when the parties co-operated in the selection of experts under that protocol fell within the court’s jurisdiction because the parties had by then engaged with each other in the process of the claim. There was however, no analogous stage in the present case, as the Pre-Action Protocol for Construction and Engineering Disputes does not usually involve experts. The judge therefore had to decide where to draw the line in such a case.

The defendant’s failure to disclose the terms on which N was engaged or for what purpose meant that the ambit of N’s instructions were unclear. Since the defendant argued that the court should distinguish between an expert instructed merely for an initial inspection and report and an expert instructed for the purposes of prospective litigation, it was for the defendant to disclose the retainer to show it was the former and not the latter. Given the lack of candour, the judge treated the defendant’s submission that N’s role was limited with “a degree of scepticism”.

The judge was prepared to find on the facts that the type of process followed in this case was sufficiently analogous to that followed under the Personal Injury Pre-action Protocol for him to conclude that N was instructed with a view to (if not in fact) being appointed as expert for the purposes of the proceedings. Particular features that were relevant included:

  1. By the time the experts met, it was already assumed in correspondence that litigation would occur.
  2. It was not a one-off private inspection undertaken by the defendant’s expert on his own; rather, there were two inspections undertaken jointly with the claimant’s experts.
  3. The experts met with witnesses and engaged with each other in the discussion of possible causes.
  4. N continued to exchange emails with the claimant’s experts after these meetings concerning the availability of evidence etc.

The judge recognised that in some cases it may not be appropriate to make any assumption that an expert instructed to investigate at the outset would, in due course, be instructed as expert for proceedings. It was appropriate in this case, however, including because litigation was already in prospect and the court had not been provided with N’s letter of instruction to demonstrate that he was not instructed for that purpose.

It was not fatal to the application that N had not produced any written report: that was only one factor to be taken into account. Other documents, including preliminary materials, can fall within the ambit of the jurisdiction.

The judge added that if, contrary to his view, N should be regarded only as an expert engaged for private pre-litigation advice, the features described above, including the early pre-action engagement between experts, were sufficiently unusual factors to make this an appropriate case to treat him otherwise.

(ii) If there was a relevant change of expert, should the judge exercise his discretion to impose a condition on the grant of permission?

The judge said that both parties had agreed with his suggestion during argument that there was a sliding scale between a “flagrant case of expert shopping” because a party did not like the damaging views expressed by its current expert and the need to replace the expert for justifiable reasons such as illness or retirement. The closer the circumstances are to the former end of the scale, the more likely it was that a court would impose a high price for permission. The closer they were to the latter, the less onerous the conditions (if any) that might be imposed.

The judge was prepared to draw the clear inference that expert shopping had occurred in this case, for tactical reasons, namely that N had concluded that a discarded cigarette was the likely cause of the fire and had informed the defendant’s lawyers of his conclusions. Key factors in reaching that decision included the defendant’s initial denial (subsequently retracted) that N had given an opinion on causation at all and the fact that N was as suitable an expert for the role as his proposed replacement. The judge concluded that, unlike the case of BMG (Mansfield) Lt v Galliford Try Construction Ltd [2013] EWHC 3183 (considered here) this case had a strong appearance of expert shopping and as such warranted waiver of privilege over documents going beyond the expert’s report.

The judge therefore ordered the defendant to disclose the October 2019 attendance note to the extent that it recorded N’s opinion on causation (but redacting all other matters). He made no order as to other categories of documents sought by the claimant because the defendant had said they did not exist.

Anna Pertoldi
Anna Pertoldi
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Caroline Tuckwell
Caroline Tuckwell
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Maura McIntosh
Maura McIntosh
Professional support consultant
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