Is there an exception to the Heck v. Humphrey rule for plaintiffs who are no longer in custody?

QUESTION PRESENTED Under Heck v. Humphrey, 512 U.S. 477 (1994), a plaintiff asserting a claim under 42 U.S.C. § 1983 that questions the validity of his conviction or the duration of his sentence must show that “the conviction or sentence has been reversed on direct appeal, expunged by executive order, declared invalid by a state tribunal authorized to make such determination, or called into question by a federal court’s issuance of a writ of habeas corpus” — the rule. Id. at 486-87. The question presented is: Is there an exception to the rule for plaintiffs who are no longer in custody, as six courts of appeals have held, or must an ex-prisoner plaintiff still satisfy the rule, as five courts of appeals have held?