Continuity mistake: When in the first pub and it turns out one guy is tee-total and will only drink water, there is a shot of the glass from the inside as the pint of water is drunk down to the bottom. In the next shot, from the side of the table, the glass has some in - around 1/3 full.
Continuity mistake: In the first story, when the guy with the balls under his chin is making a toast, the amount of vodka in the glasses changes when the camera angle changes. (00:08:30 - 00:09:30)
Continuity mistake: When they are discussing whose pinkie gets cut off, Vince grabs Craig by the neck and pushes him against the refrigerator. Craig is first shown pushed against the right hand side of the refrigerator, but whenever the camera is on him for the rest of the scene, he is shown standing against the left hand side of the refrigerator.