Continuity: In two scenes immediately before he is asked by Danny, whether he wants to play with them, the monk can be seen participating in the training.
Continuity: When 'Nitro' is bundled into the back of a prison van, he knocks a guard's hat off. As the prison van doors are slammed shut, the guard's hat is still firmly on his head.
Continuity: Flipped shot: In the opening scenes, when Danny is being chased by the police, his driving position changes from right-hand drive to left-hand drive, then back again between shots.
Revealing mistakes: During the explosion in the final scene, the wall can be seen to flex, indicating that it is made of something more flimsy than a real prison wall.