It's been too long since I've seen it to get too specific.
I don't think Jon Hamm's character was a very good person, and I liked the way his punishment fit. He's a good-looking, charming, and suave guy who can't use any of that anymore. He used people to get by, and he can't do that anymore. I know he ends up getting a guy killed, but I thought his treatment of the "cookie" was the most damning to his personality.
The other dude....I can't remember if he kills his father in law on purpose or accidentally. But I don't remember thinking his crime was unjust.