John killed him.
Probably. He was the one cutting his binds. They left it unanswered so as to use it for a future plotline.
+++++++SPOILER+++++++
1. Shirley Manson is a good singer, but terrible actress. Just because you have a cool Irish accent doesn't mean you can act.
2. My biggest question is: If that guy in the end had said the right things in the bathroom instead of the wrong things, or if the other guy had stuck around longer, would she have just stayed there and let the guy pee on her?