We are, yes. I can't say I ever wished to return to my roots quite so literally, but whatever...

[ she survived being a lab cat once. maybe this time will kill her? ]

There is no "if" about it, I believe. The evidence supports his story. Also, if he were not killing in self-defense, it would have required him to, for some reason, drag Kei to our room to kill, and also to have supplied Kei with a strange weapon that no one else has with which to attack him...that scenario makes absolutely no sense. If he were truly the instigator, it'd have played out in a very different fashion. So, we should say "Because Bigby was defending himself, no one would blame him".

Those who would are a bit suspicious, I think.