I heard the director made it intentionally ambiguous...
He got a lot of flack for it though.
--begin spoiler--
What confused me is that, since he, you know, shot the woman, why would Buddy give him his job? Is it saying that Buddy finally got respect for Guy? I don't understand why a man would step down from his high paying, great job for somebody who just shot a woman. Maybe it was because he realized how much of an asshole he was being and disgusted himself to the point where he couldn't do it anymore? I don't know
--end spoiler--
Very dark comedy. I loved it though.