From Roda Drilling Co. v. Siegal, 2009 U.S. Dist. LEXIS 4559 (N.D. Okla. Jan. 22, 2009):

The documents submitted consist of a variety of e-mail communications and attachments in which accountant Philip Holthouse is the author or a recipient and most of which also include attorneys. Plaintiffs claim either attorney-client privilege or work product protection from discovery for the documents. Defendants argue that none of the documents are subject to such protection from discovery because, under federal and New York law, there is no special privilege for communications with accountants. They assert therefore that no privilege attaches to Mr. Holthouse's communications generally, or to his communications with counsel. …

The Court rejects the assertion that communications involving and including Mr. Holthouse and attorneys working for RoDa cannot be privileged communications. Although there exists no special privilege for communications with accountants, the basis for the claim of privilege for Mr. Holthouse's communications with counsel is not the fact that he is an accountant for RoDa. The basis for the claim of privilege is that Mr. Holthouse was the functional equivalent of a RoDa employee and represented RoDa in his communications with RoDa's attorneys. See In re Bieter Co., 16 F.3d 929, 936-37 (8th Cir. 1994) (communications between a company's lawyer and its independent contractor merit attorney-client protection if the contractor is the functional equivalent of an employee of the company); In re Copper Market Antitrust Litigation, 200 F.R.D. 213, 218-19 (S.D. N.Y. 2001); Sieger v. Zak, 18 Misc.3d 1143(A), 2008 WL 598344 (N.Y. Supp) (applying In re Bieter).

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Based on the facts of this case, the Court finds that there is no principled reason to deny attorney client protection to communications involving Mr. Holthouse and counsel which in camera review reveals were primarily or predominately of a legal character and would therefore be considered privileged attorney-client communications if Mr. Holthouse were technically an employee of RoDa. Rossi v. Blue Cross & Blue Shield of Greater N.Y., 73 N.Y. 2d 588, 594 (1989) (so long as the communication is primarily or predominantly of a legal character, the privilege is not lost by the inclusion of non legal matters).

However, the Court found waiver as to a number of specific documents based on testimony at a preliminary injunction hearing and at deposition.