MMI Research Ltd v Cellxion Ltd & Ors

Accidental disclosure of a privileged document does not automatically entitle the disclosing party to injunctive relief. The court may intervene where the receiving solicitor realised, or it would have been obvious to a reasonable solicitor, that disclosure was mistaken, unless relief would be unjust or inequitable. The relevant mistake is the mistaken disclosure of the document, not merely a difference between documents or a mistake discoverable after detailed comparison. Where a document is disclosed under disclosure obligations without reliance by the disclosing party, waiver ordinarily extends no further than the document itself. Further waiver depends on whether withholding related material would make the disclosure unfair, misleading or incomplete.

The claimant brought patent infringement proceedings against the first four defendants, who counterclaimed and challenged the patent. During disclosure, the claimant listed and supplied an English draft pleading from earlier German patent proceedings, believing it to be a translation of a German pleading. It later emerged that the English document had never been filed and was a separate privileged draft.

The claimant sought orders preventing further use of the document and resisting disclosure of privileged annexes referred to in it. The defendants also sought specific disclosure of further categories of documents, including material relating to demonstrations, marketing and the HP8922 device. The central issues were whether privilege had been waived by mistaken disclosure, the extent of any waiver, and whether the requests for specific disclosure were properly focused and evidenced.

1. Privilege and mistaken disclosure. The English brief was treated as privileged and had been disclosed by mistake. The governing principles were those summarised in Al Fayed v The Commissioner of Police for the Metropolis [2001] EWCA (Civ) 780. A receiving solicitor is generally entitled to assume that privilege has been waived. Relief may nevertheless be granted where the recipient appreciated the mistake, or where the mistake would have been obvious to a reasonable solicitor, subject to equitable considerations.
2. The receiving solicitors had not appreciated the mistake. Nor would the mistake have been obvious to a reasonable solicitor. The relevant question was whether it was obvious that disclosure of the English document itself was mistaken, not whether detailed comparison or further enquiries would reveal that the English and German documents differed. Privilege was therefore waived and the defendants were entitled to use the English brief.
3. Extent of waiver. Applying the fairness principles discussed in General Accident Fire & Life Assurance Corporation Ltd v Tanta [1984] QB 100, the unreported Regina v The Secretary of State for Transport, ex parte Factortame decision of 7 May 1997, and Fulham Leisure Holdings Ltd v Nicholson Graham & Jones [2006] EWHC 158, disclosure made to comply with disclosure obligations does not ordinarily waive privilege in related documents. The question is what fairness requires in the circumstances. Because the claimant was not relying positively on the English brief, use of it without privileged annexes would not be unfair or misleading. Privilege in annex K11 and the declaration of Mr Stokes was not waived. Annexes K9 and K10 were non-privileged and were subject to specific disclosure, if they existed.
4. Specific disclosure. An applicant must identify the documents sought, explain the issues to which they relate, and provide a proper evidential basis for supposing that the documents exist or are held by the opposing party. Requests expressed in excessively general terms, unsupported by adequate evidence, will be refused. The defendants were required to disclose the search terms used for certain archive searches, but the broader requests concerning trade fairs, conferences and the HP8922 device were refused.
5. The defendants succeeded on the principal issue and some ancillary matters but were largely unsuccessful on the remaining disclosure application. The defendants were ordered to pay 50 per cent of the claimant’s costs of the applications.