Because the attorney-client privilege rests on the confidentiality of the attorney-client relationship and provides absolute protection to highly relevant communications, courts consider it to be extremely fragile. In contrast, the work product doctrine does not rest on confidentiality, and can be overcome in many situations if the adversary really needs the protected material — so courts consider the work product protection more resilient.
The difference in waiver principles between the privilege and the work product doctrine becomes most clear when the owner of a document deserving both protections discloses that document to a friendly third party. This action usually waives the privilege protection — but not the work product doctrine protection. In Westernbank Puerto Rico v. Kackar, Civ. No. 07-1606 (ADC/BJM), 2009 U.S. Dist. LEXIS 16356 (D.P.R. Feb. 9, 2009), the court held that a company disclosing to its regular outside auditor (Deloitte) the protected report of an internal investigation conducted by KPMG waived the attorney-client privilege but not the work product doctrine protection. About one month later, in Schanfield v. Sojitz Corp. of America, No. 07 Civ. 9716 (CM) (JCF), 2009 U.S. Dist. LEXIS 17354 (S.D.N.Y. Mar. 6, 2009), well-respected United States Magistrate Judge James Frances held that plaintiff’s disclosure of protected documents to his sister waived the attorney-client privilege, but not the work product doctrine protection.
Litigants should always explore the possible applicability of both the attorney-client privilege and the work product doctrine protection. The work product doctrine usually does not provide absolute protection, but generally survives disclosure to friendly third parties.