Continuity mistake: After being told that Pollux was released from prison, Sean Archer (as Castor Troy) shouts that he's Sean Archer, then grabs hold of the bars above him, with three bars between his hands. Next shot, as the guard's foot is on his hand, there are only two bars between his hands before he lets go. (00:58:50)
Continuity mistake: During the speedboat chase, when Castor Troy (as Sean Archer) shoots up the white speedboat that Sean (as Castor Troy) drives, there are numerous bullet holes on its starboard side. Four shots later, when he hits the box on the rear seat, those bullet holes on the starboard side are gone. (02:04:15)
Continuity mistake: After the jet crashes into the hangar, Sean Archer runs up the back end of a police cruiser, whose three blue flashing lights are completely shattered. In the next shot facing him, when he reaches the car's roof, two of the blue lights have repaired themselves. (00:13:45)
Revealing mistake: At Erehwon, Sean (as Castor Troy) is given steel magnetic boots to wear, for the prison's important security feature. There is a close-up of these heavy duty boots during his 'exercise'. Then, when he is taken to the clinic there is another close-up, and there are a number of changes to the boots style. More importantly, one of the side "bolts" has fallen off, revealing that it was merely glued on the prop boots.
Revealing mistake: Just as the red speedboat heads toward shore, before it crashes, the white and red truck cranes are on the dock and the white crane arm is angled backwards over the dock. In the shot facing the speedboat, as it explodes, that crane arm is now angled the opposite way, over the water, since it was used in the stunt.
Continuity mistake: When Castor Troy (as Sean Archer) says, "Every time you'll look in the mirror, you'll see my face," he proceeds to cut his face. The first cut he makes is straight down the side of his right cheek (viewer's left) and later that cut is curved and closer to his nose. This may appear to be a mistake at first glance; however, Castor's facial expression is different in the two images. When he made the cut, the cheeks were pulled away from the nose; in the second photo, the muscles are relaxed, moving the cut closer to the nose. (02:09:15)