Under certain conditions, the common interest doctrine can avoid what would otherwise be a waiver when separately represented clients share privileged communications to support a common legal strategy. As tempting as it would be to think that such clients' lawyers can automatically assure that favorable outcome by contracting among themselves for it, the doctrine is unpredictable and very risky.

In Ross v. Illinois Central R.R., the court rejected a common interest doctrine assertion – noting that "[e]ven when a common interest exists between parties, it is clear to us that the client must, at the time of the disclosure, have an agreement with the receiving party that that party will treat the information as privileged." --- N.E.3d ---, 2019 IL App (1st) 181579, ¶ 44. The parties arguing for the doctrine's application acknowledged they "had no such agreement, written or otherwise."Id. ¶ 45. Several weeks later, the court in JNL Management LLC v. Hackensack University Medical Center, followed states such as Hawaii, Maine, New Hampshire, New York and Vermont in rejecting a position advanced by Drinker Biddle and its client "that anticipated litigation is not a necessary requirement for the common interest doctrine to protect waived attorney-client privileged communications." Civ. A. No. 2:18-CV-5221-ES-SCM, 2019 U.S. Dist. LEXIS 91358, at *26-27 (D.N.J. May 31, 2019). A few weeks before that, the Federal Claims Court offered some good news. The court held that for the common interest doctrine to apply, "[t]he third party [to which privileged communications are disclosed] need not be a litigant in the present suit, or any suit, but its interest shared with the party in the present suit must be a legal one, not merely commercial." Order at 4, SecurityPoint Holdings, Inc. v. United States, No. 11-268C (Fed. Cl. Apr. 16, 2019), ECF No. 403. That is a more favorable approach than some courts take -- requiring that each common interest doctrine participant establish its own requisite involvement in or anticipation of litigation.

Unfortunately, courts never seem to settle on a uniform or expansive common interest doctrine. Corporate clients and their lawyers should always be wary of thinking that they can contractually assure protection that the law may not recognize.