Alive. Bert took it as a good sign that Leon used this word to describe himself. Some people didn't think of vampires as 'alive'. There were even some vampires who didn't. But Leon had said alive. This spoke to some sort of hope for the future, even if only a vague hope.
As for Leon's question, Bert saw no reason to not be forthcoming. "If I have anything to do with it, he won't be. Andrei did violate the school's rules, and a serious rule at that, but it was for a good reason, I think. Other kinds have done the same in the past for similar reasons, and they've gotten away with just some detentions. No reason it shouldn't be the same here." He couldn't speak for the other staff, but that was Bert's opinion on the situation.