Mistaken disclosure - the principles and the practicalities

The Court of Appeal has looked at the principles applicable when an otherwise privileged document has been mistakenly disclosed. How can such errors be prevented?

In today’s world of hundreds of emails a day flooding into your inbox, it is not surprising that disclosure of documents in English court proceedings can be a daunting and complex task. This is especially so when the documents include privileged materials.  

In Atlantisrealm Limited v Intelligent Land Investments (Renewable Energy) Limited the Court of Appeal considered the principles of mistaken disclosure of privileged material in the “electronic age”.  

The disclosure exercise

The defendant in the Atlantisrealm case provided access to its solicitors to just over 7,000 documents for review as part of the disclosure exercise in the proceedings. An initial review of all those documents was undertaken by junior solicitors and trainees. A more senior member of the team reviewed only those documents flagged by the initial reviewers where they were unsure as to whether the document was relevant or privileged. 

In the event, nearly 5,000 documents were disclosed to the claimant. This number included an email between the defendant and its (then) solicitors which, whilst not fatal to the defendant’s case, contained information helpful to the claimant. This document was not reviewed by the more senior member of the team prior to disclosure, as it had not been flagged by the initial reviewers.

When inspection of the documents was provided to the claimant, the associate at the claimant’s solicitors reviewing them did not appreciate that the email had been disclosed in error. A couple of months after inspection, the associate shared the email with the partner on the case and the email was shared thereafter with the claimant and its witnesses for comment.

A month or so later, the email in question was drawn to the attention of the defendant’s solicitors ahead of a planned settlement meeting. The defendant then applied for an injunction requiring the claimant to delete all copies of the email and restraining the claimant from using the email in the proceedings. This was on the basis that the court’s permission under CPR 31.20 is required “[w]here a party inadvertently allows a privileged document to be inspected” and “the party who has inspected the document” seeks to “use it or its contents”.

When can use of a mistakenly disclosed document be restrained?

At first instance, HHJ Klein refused to grant such an order on the basis that the disclosure of the email was not a mistake, but was deliberate, and, even if it was a mistake, it was not an obvious mistake such that an injunction should be granted in the manner sought.

Following the principles set out in the leading Court of Appeal case in this area, Al-Fayed & Ors v The Commissioner of Police for the Metropolis & Ors, but with the addition of a “modest gloss” to those principles, the Court of Appeal disagreed, allowing the injunction in favour of the defendant.

The full principles from Al-Fayed are helpfully set out in Jackson LJ’s judgment in the Atlantisrealm case, but the key elements bear repeating:

  • Generally speaking, a party inspecting another party’s documents is entitled to assume that any privilege which might otherwise have been claimed for such documents has been waived, even if otherwise privileged material is included in those documents by mistake.  
  • However, the court may restrain the other party from using the document if it has been made available as a result of an obvious mistake. A mistake is likely to be held to be obvious if the solicitor receiving the documents appreciates a mistake has been made before making use of the document or it would be obvious to a reasonably competent solicitor that a mistake had been made.

In Atlantisrealm, the Court of Appeal accepted that while the associate at the claimant’s solicitors did not appreciate that it was an obvious mistake, the partner did. The multiple solicitor situation had not been considered in Al-Fayed (or any subsequent cases), but the Court of Appeal decided that provided any solicitor appreciates the obvious mistake before use is made of the document, the court can grant relief on the basis of the Al-Fayed principles. 

What are the lessons to learn?

The Court of Appeal in Atlantisrealm took an openly sympathetic view of the difficulties faced by law firms in conducting a disclosure exercise in the “electronic age”. In Jackson LJ’s judgment, he commented that “even with the help of sophisticated software, disclosure of documents can be a massive and expensive operation. Mistakes will occur from time to time” and that inadvertent disclosure of privileged material is “bound to happen occasionally”. He also commented that the disclosure exercise undertaken by the defendant was “in line with what one would expect in any case where people, rather than machines, are carrying out the disclosure exercise”.

Whilst it is reassuring to see the courts uphold a party’s claim to privilege in such circumstances, it is clearly undesirable to be in this situation in the first place. Indeed, Jackson LJ commented that the courts should not be troubled with such cases and parties should not be devoting their resources to contesting such issues. However, the courts will not grant relief in all cases of mistaken disclosure - it happened at first instance in Atlantisrealm as well as in another case cited in Jackson LJ’s judgment, Rawlinson & Hunter Trustees SA & Ors v Director of the Serious Fraud Office (No 2).

So what can parties and their lawyers do to reduce the risk of the disclosure of privileged material? There are a range of steps that a disclosing party’s solicitors can take to prevent the accidental disclosure of privileged material. Some steps will be more appropriate and cost effective than others, depending on the nature and extent of the review.

  • Review by qualified lawyers of all documents marked for disclosure by first level reviewers (not just those marked unclear or unsure). In Atlantisrealm, a mixture of qualified and unqualified fee earners undertook the first level review, but only "unclear" documents were reviewed by a more senior qualified lawyer.
  • Targeted review by qualified lawyers of all documents to/from solicitors, using tailored searches in a document review platform. Again, if this had been undertaken in Atlantisrealm, the document would not have been disclosed.
  • Once privileged documents have been identified using tailored search terms, email threading and near duplicate identification analytics that are now widely available in most document review platforms can be used to locate additional privileged documents that may have been missed. By using a review platform to group together all of the various emails in an email chain, it can be checked whether a specific email has been marked as privileged, but also whether any forwards, replies or CC’s of that same email have been caught. Likewise, near-duplicate analysis can be used to identify documents that are textually similar to documents that have been designated as privileged to ensure that drafts or versions of similar documents are identified.
  • Although not an issue in Atlantisrealm, checks should be undertaken on redacted documents to ensure that not only is the PDF version redacted correctly, but also to ensure that the extracted text version accompanying the PDF does not contain the redacted wording.
  • Similarly, searches should be set up to isolate privileged or part-privileged (redacted) attachments to emails and ensure they are all converted to, and provided to the other party in, PDF form. If the emails themselves are provided in "native" Outlook email form, rather than PDF form, the inspecting party will be able to open up and review the privileged or part-privileged attachments in their original (ie non-redacted) form.
  • Disclosure lists are now generally generated electronically from document review platforms. If the disclosure set contains, for example, non-privileged emails with a mixture of privileged and non-privileged attachments, not only will the privileged attachments need to be redacted in their entirety and the whole "family" of documents converted to PDF, but the metadata (such as the date, sender, recipient, email subject etc.) for the privileged document will need to be redacted manually. Otherwise, the metadata provided on inspection will include such potentially privileged information and so will the automatically generated disclosure list.  
  • The review should incorporate quality control measures, including the review of a sample set of documents marked as not to be disclosed by the first level reviewers to make sure that they are coding the documents correctly. 

The above steps are not exhaustive, but should give a flavour of the potential problems that arise in the disclosure of electronic documents. 

Whilst Atlantisrealm is a welcome and reassuring clarification of the law regarding mistaken disclosure, careful thought must be given in the design of a disclosure process so as to to avoid privileged material accidentally being disclosed. 



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This document (and any information accessed through links in this document) is provided for information purposes only and does not constitute legal advice. Professional legal advice should be obtained before taking or refraining from any action as a result of the contents of this document.