I would spend as much money possible to hire the best attorney he can find. Don't settle for just any douche bag attorney. I'd rather be in debt, than be in jail. From what you said it sounds like he just passed out and it was an accident, but cops and lawyers are pieces of shit, so they might try to put him away considering somebody died. I also wouldn't talk to anybody except his attorney. It's already bad enough he has to live with the guilt of killing somebody, but going to jail for something you didn't do is even worse.