Continuity mistake: After Johns dies and Riddick is talking to Fry you see in one shot that only the bottle that Fry is holding is lit up, yet in the very next shot you see that all three, Fry, Jack, and the Muslim kid's bottles are lit.
Continuity mistake: When the guy with glasses (Paris) is chilling with his fan, there is some material stuck out between his right ear and his right shoulder. In the next shot when he retracts the fan, it's gone.
Continuity mistake: When Riddick powers up the ship the first time during the escape, he is seen with blood on his left ear. This blood was not there on any previous shots and promptly disappears in the next shot.