Can a party waive attorney-client privilege if they are compelled to produce documents that have not been produced voluntarily?

Although the privilege may be waived by the voluntary production of otherwise privileged documents, it is clear that the privilege was not lost through the government's discovery of the letter in the course of executing its search warrants. We held in Transamerica Computer v. International Business Machines, 573 F.2d 646, 651 (9th Cir.1978), for example, that "a party does not waive the attorney-client privilege for documents which he is compelled to produce." The government asks us to hold, however, that the privilege was waived when appellant failed to pursue the timely return of the letter. ²