Continuity mistake: When Pnub's head is picked off the kitchen table at the end of the hand-cutting scene, the ring of blood that formed around Pnub's neck stump is joined with the larger pool of blood that it came from. When Pnub and Mick come back to the kitchen later on, the ring is no longer attached to the larger pool. Blood does not evaporate like that when it dries.
Anton: Hey, I didn't kill anyone on purpose, okay?
Mick: Yeah, well, we weren't in hell! I mean, there was this bright white light at the end of a long tunnel, right, and there was these chicks' voices, and that music.
Pnub: Yeah, kinda uncool music, like, Enya. And these chicks' voices, they were saying, "come to us, come towards the light."
Anton: So what happened?
Mick: We figured, fuck it, I mean, it was really far.