The High Court has refused to grant an injunction to prevent a party using privileged material in a letter exhibited to an opponent's witness statement filed in support of an interim application, where the material had been included in error but the error was not obvious to the recipient: Pickett v Balkind [2022] EWHC 2226 (TCC).

The decision illustrates that, even if an injunction would otherwise be warranted where there was no obvious mistake, the court may refuse to grant an injunction where the privileged material reveals some sort of wrong on the part of the disclosing party - here a potential serious breach of court guidance relating to the preparation of experts' joint statements. That appears to be the case whether or not there is sufficiently serious misconduct to mean that the material was not privileged in the first place under the "iniquity principle" (ie that privilege does not apply to protect communications made in furtherance of a crime, fraud or equivalent conduct). It is perhaps not surprising, given that an injunction is a discretionary remedy and may be refused where the claimant does not approach the court with "clean hands".

The case is also a reminder that legal advisors must be careful not to interfere in the preparation of experts' joint statements. The lawyers' role is limited to identifying issues which the statement should address; they should not invite the experts to consider amendments to the draft statement save in exceptional circumstances, where there are serious concerns that its terms may be unclear or misleading – in which case those concerns should be raised with all experts involved in the joint statement.

Finally, on a separate point, the decision suggests that where a party serves expert evidence which refers to and relies on privileged material, that will act as an immediate waiver of privilege even though the expert has not yet been called to give oral evidence.


The underlying dispute was a tree root subsidence claim relating to residential property in Sutton, Surrey. The parties each had permission to rely on expert evidence from two experts, an arboriculturalist and a structural engineer. Directions were given for the filing of joint statements with individual experts' reports to follow.

In May 2022 the claimant's solicitors informed the defendant's solicitors that the claimant's structural engineer, Mr Cutting, would not be available to give evidence at the trial that was then listed for mid-July 2022 as he would be recovering from eye surgery. The defendant did not agree to the claimant's request for an adjournment, and so the claimant filed an application notice seeking an adjournment.

The adjournment application was supported by a witness statement from the claimant's solicitor, Mr Charlesworth, which exhibited a letter from Mr Cutting dated 3 May 2022 (the "Letter"). As well as explaining about his upcoming surgery, the Letter referred to comments received from the claimant's counsel on the experts' draft joint statement and attached a copy of the draft for comments from both solicitors and counsel.

The defendant's solicitors wrote to the claimant's solicitors expressing concern that the Letter revealed a breach of the guidance at para.13.6.3 of the TCC Guide, which states:

"Whilst the parties' legal advisors may assist in identifying issues which the statement should address, those legal advisors must not be involved in either negotiating or drafting the experts' joint statement. Legal advisors should only invite the experts to consider amending any draft joint statement in exceptional circumstances where there are serious concerns that the court may misunderstand or be misled by the terms of that joint statement. Any such concerns should be raised with all experts involved in the joint statement."

The claimant's solicitors asserted that the material in the Letter was privileged and the fact that it was included in full in the exhibit (rather than in redacted form) was an obvious mistake. They filed a new application notice with a new witness statement which did not refer to or exhibit the Letter, and applied for an injunction to prevent the defendant using the original statement and the Letter. The witness statement from Mr Charlesworth supporting the injunction application stated that the Letter had included Mr Cutting's comments in respect of an "aide memoire" the solicitors had sent him in connection with preparation of the joint statement, and that including this section of the Letter in the exhibit had been "an inadvertent and obvious error".

The defendant issued a cross-application seeking production of the "aide memoire" and permission to cross-examine Mr Cutting at trial as to the preparation of the joint statement and the completeness of the statement of instructions in his expert's report. This was on the basis of CPR 35.10(4), which provides that the material instructions to an expert, on the basis of which their report was written, are not privileged against disclosure, but the court will not order disclosure of any specific document or permit the expert to be questioned about their instructions unless there are reasonable grounds to consider the expert's statement of their material instructions (which must be included in their report) to be inaccurate or incomplete.

Separately, the defendant sought an order that the claimant should produce a copy of an earlier expert report by Prior Associates (Mr Cutting's firm) which had not been disclosed but was referred to in the report of the claimant's arboriculturalist (Mr Pryce). This was under CPR 31.14(2), which provides that a party may apply for an order for inspection of any document mentioned in an expert's report. The claimant responded with an application to replace the original report of Mr Pryce with a version which did not refer to the Prior Associates report.


The High Court (HHJ Matthews sitting as a High Court Judge): (i) refused to grant an injunction to restrain the defendant from using the Letter or its contents at trial; (ii) refused to order the production of the aide memoire but gave the defendant permission to cross-examine Mr Cutting on it at trial; and (iii) ordered the claimant to produce the earlier Prior Associates report for inspection by the defendant.

Injunction application

The judge referred to the applicable principles, as set out by Clarke LJ in Al Fayed v Commissioner of Police of the Metropolis [2002] EWCA Civ 780, including that:

  • A solicitor considering documents made available by the other party to litigation is generally entitled to assume that any privilege which might otherwise have been claimed in them has been waived.
  • Where a party has given inspection of privileged documents by mistake, it will generally be too late to claim privilege in order to attempt to correct the mistake by obtaining injunctive relief.
  • However, the court can intervene to prevent the use of the documents where justice requires, as for example where inspection was procured by fraud.
  • In the absence of fraud, all will depend upon the circumstances, but the court may grant an injunction if the documents have been made available for inspection as a result of an obvious mistake.
  • There are many circumstances in which it may nevertheless be held to be inequitable or unjust to grant relief, but all will depend upon the particular circumstances.

In this case, the judge accepted Mr Charlesworth's evidence that he had included an unredacted copy of the Letter in the exhibit inadvertently, but also accepted the defendant's solicitor's evidence that on receiving the exhibit he had not appreciated there was any error. The judge also held that the error was not "obvious".

The judge expressed some doubt as to whether the relevant section of the Letter was privileged in the first place, given that it revealed potentially a serious breach of para 13.6.3 of the TCC guidance, and (as the principle is sometimes expressed) there is no confidence in iniquity. If the Letter was privileged, the question was whether that privilege survived its disclosure in unredacted form to the defendant, ie whether privilege was thereby waived – which, the judge said, was intimately tied up with whether an injunction would be granted to restrain its use.

Even if an injunction would otherwise be justified, despite the mistake not having been obvious, the judge considered that it would not be right to grant an injunction since the Letter revealed a potentially serious breach of the TCC Guide. That conclusion was strengthened by the fact that the defendant had relied on the Letter to raise its concerns with the claimant immediately, and had received no satisfactory response. It would promote a sense of injustice in the defendant to leave that concern hanging, unanswered.

Application under CPR 35.10(4)

The judge accepted the claimant's submission that not every communication between experts and those instructing them is part of their "instructions" for the purposes of rule 35.10. The aim of the rule is to ensure that the "factual basis" for the expert's opinion evidence is apparent to the reader. Accordingly CPR 35.10 is concerned with the question of the factual (and sometimes the legal) basis for the expert's opinion. These are matters which experts cannot know for themselves but for which reliance must be placed on others.

The question of whether an expert is properly independent of the instructing party is a different matter, and so communications going to that issue – if they did not address the basis for the opinion – are not covered by CPR 35.10. The court's power to order disclosure of a specific document was not therefore engaged merely because there were reasonable grounds to consider that the statement of instructions did not refer to such communications.

Here, the judge was not satisfied that the aide memoire formed part of the expert's instructions and so there was no power to order its disclosure under CPR 35.10.

However, the judge considered that there was a proper basis for cross-examining the expert on the aide memoire as it went to the issue of independence, and (seemingly) the court was satisfied that such matters would not be privileged, as privilege in the Letter (which referred to the aide memoire) had been waived.

Application for production of Prior Associates report

The judge considered the position on the assumption that the Prior Associates report was a privileged document, so that the court could order its production only if privilege had been waived. That depended on whether Mr Pryce's expert's report merely referred to the earlier report or whether it relied on (or deployed) its content. Only in the latter case would privilege be waived. Here the judge was satisfied that Mr Pryce did rely on the report to reach his own conclusion.

The judge also considered whether the position was affected by the fact that Mr Pryce had not yet given oral evidence – ie whether the claimant could withdraw its decision to deploy the material in the original report, and therefore prevent a waiver. He concluded that it could not. CPR 35.11 provides that, where a party has served an expert's report, any party may use that report as evidence at trial. Therefore, whether or not the claimant was permitted to serve a further report from Mr Pryce, it could not prevent the original report being admitted in evidence.

Accordingly, privilege had already been waived in the Prior Associates report, and it should be disclosed under CPR 31.14(2).

The content of this article is intended to provide a general guide to the subject matter. Specialist advice should be sought about your specific circumstances.