If there is one area of the law which has always seemed to me to be all over the place (though I never really sat down and tried to nut it out), it’s the law of privilege in its application to the inadvertently disclosed document. The latest English decision is MMI Research Ltd v Cellxion Ltd and others  All ER (D) 142. It says that there will be a waiver unless the recipient ought to have known that a mistake had been made. In this case that could not be made out. CMS Cameron McKenna’s Law Now note on the case is here.