Instead, the civil procedure nerd in me gravitated toward Will v. Hallock, which presents two civil procedure issues that just might show up on final exams. (Law students, do I have your attention yet?) The one the parties concentrated on is, of course, not the one the Court cared about the most. Justice Souter (8–0) writes that:
[T]he collaterally appealing party was vindicating or claiming a right to avoid trial, in satisfaction of the third condition: unless the order to stand trial was immediately appealable, the right would be effectively lost. Those seeking immediate appeal therefore naturally argue that any order denying a claim of right to prevail without trial satisfies the third condition. But this generalization is too easy to be sound and, if accepted, would leave the final order requirement of [28 U.S.C.] § 1291 in tatters.
Slip op. at 5 (hyperlink added). This should look familiar: It's one way that qualified immunity gets described, both in textbooks and in practice. The Court, however, held that what was at issue in Will was not the right to avoid trial, but the right to avoid adverse judgment—which fails to satisfy the conditions of the collateral order doctrine (which, in turn, allows certain appeals to be taken before final judgment). The various customs officers wanted to take advantage of an exception coming from the Federal Tort Claims Act.
Sadly, this was a predictable result. As the Court notes, "Prior cases mark the line between rulings within the class and those outside" (slip op. at 4).
[I]t is not mere avoidance of a trial, but avoidance of a trial that would imperil a substantial public interest, that counts when asking whether an order is effectively unreviewable if review is to be left until later.
Will basically boils down to the question of whether the defense of claim preclusion rises to that level. As the Court makes clear, it doesn't in civil cases. This was predictable based on well-settled precedent. I suspect that the only reason the appeal made it even this far is that the underlying case is a Bivens action against government agents… and that the individual agents are not paying for their own attorneys.