Continuity mistake: In the restaurant scene where the cigar dispute takes place, Bruce gets his fingers broken on his right hand. Later on in the movie, the two FBI agents encounter Bruce in his yellow Hummer. When he rolls down his window, his bandaged LEFT hand is shown.
Continuity mistake: When Snake falls toward the water with the "kingpin's suitcase", the gun is in his right hand and he's gripping the heavy suitcase in his left hand. Yet, in the last shot of him underwater the gun and suitcase have switched hands. Interestingly this is not a flipped shot, the watches are still on his left wrist.
Continuity mistake: When Desalvo's bullet hits Arthur Herk's TV the glass shatters and the bullet hole is visible on a black background towards the upper left. But in following shots much more of the glass is intact, with a large jagged hole in the glass surrounding the area of the bullet's impact.