I liked this suggestion so much — and think it makes a poor 20k ability (sorry Andy) — that I'm suggesting it directly:
Temporarily lock questions from being edited, to prevent ridiculous edit wars like this one.
This could be handled by automatically locking any post with E edits in T minutes. It could be limited to just a day or two, then automatically unlocked, if moderators finding time to review the post is a concern. However, it could require a new locking type, as I believe posting comments on these questions might still be useful.
For E=10, T=60, I don't remember any false positives (barring quickly-wiki'd, discussed below), but it would cover the mentioned case, the "bomb effing USA" troll (okay, he used several posts, but it would've slowed him down and reduced frustration for important users), and others.
I expect E and T need tweaked, with an attempt at gauging effectiveness.