Although most jurisdictions agree on many basic privilege issues, some important variations remain. The most important involves a few states' rejection of the majority Upjohn v. United States, 449 U.S. 383 (1981) rule protecting corporations' lawyers' communications with middle and lower level corporate employees. But there are other significant distinctions among states that can make a big difference in a corporate context.

In Mooney v. Diversified Business Communications, Dkt. No. SUCV2016-3726-BLS2, 2017 Mass. Super. LEXIS 133 (Mass. Super. Ct. July 20, 2017), a corporation's former CEO/director (now adverse to the corporation) sought access to privileged communications from his time at the corporation. The court acknowledged that "[t]he choice of law issue is an important one" -- because under Delaware law "former directors or officers are entitled to privileged communications created during their tenure," while other states (including Massachusetts) "do not permit former officers and directors to access privileged information for use in litigation where the corporation asserts a privilege." Id. at *6, *7. The court had to decide between applying (1) Delaware law (because that is the defendant's state of incorporation), or (2) Massachusetts law (under the Restatement (Second) of Conflict of Laws § 139 choice of law approach). The court applied the latter standard in denying plaintiff access to the privileged documents.

Although privilege choice of law disputes rarely arise, they occasionally have dispositive effects.