Continuity mistake: When Nicholas Cage is being escorted to fetch the roll of film from his car, there are a few scenes where the accountant is holding a gun to Nicholas's head. When the camera is directed at the accountant, two hands can be seen grasping the gun, but when the camera is facing Mr Cage, initially there are two hands but after the next switchback there only appears to be the one! (01:20:50)
Continuity mistake: After Machine cuts Max's throat, Welles runs toward him and is thrown down by Machine. Then the shot cuts to Poole (Gandolfini) kicking Welles with Machine running up. Then a shot or two later when Machine and Poole are beating Welles it cuts and Poole is kicking Welles and Machine is not around. (01:22:10)Joel Amos Gordon
Other mistake: In the scene where Max is all beaten up, Machine slashes his throat and you can clearly see that the knife's blade is dull, because there's no cut or blood. (01:21:55)
Continuity mistake: When Tom and Eddie get to the building where Mary Anne was killed, it's dark outside, yet when they walk through the door, it appears to be daytime.
Visible crew/equipment: When Tom goes to talk to Max the second time at the porn shop, just as he gets to the counter, you see the boom mic on the left top of the screen.
Character mistake: Throughout the whole movie, Mary Anne has an e at the end, yet in the note her mother wrote to Tom, Anne has no e at the end. It even has an e at the end in the ending credits.
Character mistake: Mary Ann's mother's name is Janet. At the end when Tom is reading the note she wrote, she misspells her own name as Janent.