In a recent decision, the High Court found that the claimant’s reference to an expert’s preliminary report in the context of a security for costs application had not amounted to a collateral waiver of privilege, so the report itself did not have to be disclosed: Two Renewables Ltd v Reeves  EWHC 789 (Ch).
It is well-established that, where a party relies on privileged material to support its claim, it may be required to disclose other privileged material relating to the same issue or transaction. This is due to the principle of collateral waiver, or the “cherry picking rule”, which is designed to avoid the unfairness which might result if parties were permitted to rely on privileged material out of context.
In the present case, the court found that the claimant had relied only on the effect of the report, rather than its content – a distinction which has been applied in other cases, but which is often a very fine line. The decision also suggests that a collateral waiver may be less likely to result where a privileged document is deployed only for a limited purpose which does not go to the merits of the claim (here, to rebut a suggestion that the claimant’s liquidators could not possibly believe the stated quantum of the claim).
In practice, however, any decision to refer to privileged material in support of a party’s position – whether an interlocutory stage or at trial – should be considered very carefully. It may be difficult to predict in any given circumstances whether a collateral waiver will result or how far it will extend. Continue reading