There's nothing wrong with wanting him to hit rock bottom (in your experience that would be to hurt himself) in order to WANT to get better. I simply read this as him having an excuse to drink - his invite to the pub he had to turn down, the "in jail" comment, and if he's "leaving you" then why not, right? (In his mind) Enjoy your peaceful evening. He'll be back. Is he working any kind of a program?