Privileged material: The high stakes of inadvertent disclosure

Summary

In a recent decision by the High Court in The New Lottery Co Ltd v Gambling Commission [2025] EWHC 1058 (TCC) concerning the inadvertent disclosure of privileged documents by the Gambling Commission, the court granted the Claimant (New Lottery) partial permission to use privileged documents that had been inadvertently disclosed by the Gambling Commission. In deciding the case, Mrs Justice Jefford applied the principles set out in Al Fayed v Commissioner of Police of the Metropolis ([2002] EWCA Civ 780) to a case involving very large quantities of electronic documents. This decision is of particular significance for cases involving a substantial volume of electronic documents (3 million in the case at hand), often with multiple versions, and a multi-tiered review procedure.

Background

The parties were in dispute in relation to the Fourth National Lottery Competition. 

The extent and complexity of the document review were considerable. The Gambling Commission collected over 3 million documents over a four and a half year period. This included privileged documents produced by in-house counsel. There were 67 first and second level reviewers from two law firms and 330,000 documents were manually reviewed.

During disclosure, the Gambling Commission disclosed a total of 53,000 documents in two tranches. The Gambling Commission subsequently contended that it had inadvertently disclosed a total of 4,321 privileged or partially privileged documents, the privilege in which the Gambling Commission did not intend to waive. The dispute eventually focused on 128 documents in 20 categories which New Lottery wished to rely on but faced resistance from the Gambling Commission.

New Lottery later made an application, seeking the Court’s ruling as to whether it could rely on documents the Gambling Commission asserted to be privileged but had been disclosed inadvertently.

The Applicable Civil Procedure Rule and Principles

The Court considered CPR 31.20 to apply in this case and that the relevant principles were set out in Al Fayed v Commissioner of Police of the Metropolis:

• A party (and their solicitors) must decide what privileged documents they wish the other party to see (or otherwise) before producing the documents for inspection.
• A solicitor considering documents produced by the other side in the proceedings does not owe a duty of care to the disclosing party. Generally, the solicitor is also entitled to assume that any privilege which might otherwise have been claimed for such documents has been waived.
• In such circumstances, if a party has produced documents for inspection and, inter alia, provided privileged documents produced inadvertently, it is generally too late for the disclosing party to claim privilege in order to attempt to correct the mistake.
• However, the Court has jurisdiction to intervene to prevent the use of documents already produced where justice requires, for example, as a result of an obvious mistake.
• Whilst it will ultimately be dependent on the particular circumstances of a given case, a mistake is likely to be obvious where either of the below applies:
  • the solicitor appreciates that a mistake has been made before using the documents; or
  • it would be obvious to a reasonable solicitor in their position that a mistake has been made.
• Where a solicitor honestly concludes that documents made available for inspection have not been produced by mistake after giving detailed consideration to the matter, this fact will be a relevant – and potentially important, though not conclusive – indicator in determining whether it would be obvious that a mistake had been made. However, the decision remains a matter for the court to make.

The issue

The Court considered the issue to be whether it should have been obvious to a reasonable solicitor with knowledge of the case and who conducts a proper disclosure review that a document had been inadvertently disclosed. What constitutes ‘a reasonable solicitor’ and ‘a proper disclosure review’ is assessed on a case-by-case basis. 

In relation to “the reasonable solicitor”, the Judge considered the following factors that may be taken into account: 

• The reasonable solicitor is one with a reasonable knowledge of both the issues in the case and for disclosure. That would include whether there were any matters on which it might reasonably be thought that the disclosing party would disclose documents over which it might otherwise assert privilege. 
• The reasonable solicitor is entitled to start from the position that the disclosed documents have been deliberately disclosed. 
• The reasonable solicitor is entitled to consider the character of the disclosing firm and the matter in which disclosure is given. If a highly experienced firm undertakes a sophisticated disclosure exercise, one would not expect the process to lead to inadvertent disclosure of privileged documents. 
• In relation to the volume of disclosure, it might be said that a large volume would make it more likely that mistakes would be made and that it might be less likely that any errors should be obvious to a reasonable solicitor. 

The ruling and key takeaways

The Judge granted New Lottery partial permission to use some but not all of the documents at issue.

Key notes in relation to the judgment:

• Version control: The judgment highlights the risks posed by systems that save every consecutive version of the same document whenever any change/alteration is made, this increases the risk of disclosing different versions of the same document. The issue will become even more complicated where redactions are required for such documentation: different reviewers may make different redactions, some of which may overlap among different versions but some may not. Extreme care needs to be taken with such documents.
• Factors relevant to obviousness of mistake: relevant factors to be considered when one determines whether the disclosure was obvious include:
  • The nature and content of the documentation;
  • Whether there was a good reason to waive privilege;
  • The extent and complexity of the disclosure exercise;
  • Whether a large number of privileged documents had been disclosed.
• Court’s approach: whilst there are no rigid rules, the Court is more likely to refuse permission to rely on inadvertently disclosed privileged documents if it would have been obvious to a reasonable solicitor conducting a proper review that the disclosure was a mistake.
• Reviewing multiple versions: where the disclosure platform generates multiple versions of the same document set and where a version of a disclosed document contains privileged material and it is unclear as to whether the disclosure was intentional, a reviewer should check at least one other version of that document, if available. If there is consistency between the versions, the consistency will suggest deliberate disclosure, otherwise, it may suggest inadvertent disclosure.
• Redacted documents: if a reviewer is uncertain as to whether a redacted document has been produced inadvertently, the reviewer should compare it with other version(s) in the same document set if there is any available.