I think that there are two things I feel really confident in saying:
1. bb2112 is 100% proven, by mathematical proof (with one exception that I'll have to discount).
2. He was spared because one of the persons last night didn't reveal their card, or because the last wolf didn't believe bb when he said he had a daydreamer card, or because the wolves didn't see it.
On numero uno there, the fact that we're down to one wolf eliminates the possibility of bb2112 being a wolf, barring the rather long odds that he played a Spartacus card on the day 1. I'm discounting that, I think. If that is the case, congrats bb2112. You won the game for your team. Barring that, though, I think that in order for bb2112 to be a wolf, theo would also have to be a wolf, and that requires the presence of four wolves, which isn't possible. Theohall can still be a wolf. bb2112 though is not.
So. Why's he still alive if he's proven? Maybe the wolves--ok, wolf--just didn't get it that bb was proven. That's possible.
I think more likely though is that they figured that if someone either was deceptive about their card play or plain old didn't say what card they played, it may have kept the wolves at bay for fear of hitting a shield card.
I think right now it would be a fairly bad strategy to say what cards we're using/playing. The wolves need to think that someone is holding a shield card and using it on bb2112.
"It's my manner, sir. It looks insubordinate, but it isn't, really."