In the scene where they found the abandoned sight; they found a ship to get home in. Riddick was outside looking into another part of the sight. He had been beaten up a bit by the other when they found out the guy digging the hole died. They accused Riddick and someone hit him in the head with the butt of a gun. They have a 'party' since they found the ship and Riddick has a bruise on his temple when the camera shows everyone, then, when they do a close up on Riddick, surprise! The bruise is gone. The camera zooms out to the rest of the group with Riddick in the back, and the bruise is there again.