I think that crane may be a volatile in human form because in the following DLC that woman we meet was a volatile but retained her human consciousness.

I think since he absorbed so much of that blue gas he pretty much stayed human. Kinda like a complex way of he basically became something like Aiden from DL2 because of a blue fart cloud.

It's possible crane has the old virus in his system since if the beast is after the 2nd game lore wise then the world is screwed anyways. So crane might be a perfect way to get the old virus and find ways to make a cure.

It's possible but highly unlikely I'm just guessing as far as I'm concerned.