So I just locked this answer after two people flagged it due to unusual edit activity. Turns out, there were over 700 rollbacks on that answer over the last two days.
Usually, the system automatically raises a "possible rollback war" flag for this so that we can step in before things go too far. That never happened here, and near as I can tell it didn't trigger because the post was community wiki.
I think we should still be notified when something like this is happening on a community wiki post, because we'll probably want to do something about that. It's an edge case, I know, given the relatively small number of community wiki answers out there, but I think the system should still raise flags on this.