Continuity mistake: When Joe is fighting the high school footballers, he picks up the football boot by the heel with the toe pointing forward. When the camera cuts to the screaming girl he is holding the boot the other way around, with the toe pointing backwards. The camera cuts back, and the boot toe is facing forward again.
Continuity mistake: After the "Single Shot" fight sequence, watch closely as the camera cuts and Joe is stabbed in the back. The background (and the beaten-up henchmen strewn about on the floor) completely changes between shots. A section of the fight was cut out by the studio for pacing reasons, causing the mistake.