Kenny wasn't really reasoning. He was he was freaking out about losing his wife and kid. I don't think he'd have killed Larry otherwise, even though he did hate the man. Both he and Lilly fucked up in the heat of the moment, but they're similar people. Even similarly hypocritical. It would be nice for Lilly's character to have closure, in one way or another.
The saving of Christa is even more heroic imo.