(at around 4 mins) When Captain Spaulding and Stucky are having their conversation in the very beginning and Stucky is handed the bathroom key it is on a hand that is flipping the bird, however when the gunmen pull him out of the bathroom he is holding the key on a hand that is giving the devil horns and also missing his glasses.
(at around 6 mins) After Stucky is pulled out of the bathroom, the way he is holding the items in his hands changes between shots.
(at around 3 mins) When Spaulding hands Stucky the bathroom key it's attached to a hand that is giving different gestures as the camera angles change.
(at around 39 mins) When the side window of the car driven by the four victims is broken, it's regular pane glass, yet cars of that age use tempered glass. Later scenes of the same car with broken windows also show broken tempered glass.
(at around 6 mins) When Stucky and Wick are arguing, the color of the revolver Wick is holding alternates from silver to a dark gray several times.
(at around 52 mins) After Baby Firefly mutilates and scalps Jerry, he is later seen in the film with his face still intact and without damage. After sustaining the type of injury inflicted upon him by Baby, realistically his face likely would have been swollen, heavily bruised and full of broken capillaries.
(at around 57 mins) Officer Nash talks about his fear of dogs. He says when he was 8 years old he was bitten by a Cocker Spaniel, however the next time he mentions it it was his ex girlfriend's Cocker Spaniel.
On the DVD "Scene Selection" menu, Bill Moseley's character is standing in the grave yard speaking about facts of life. During his speech, he will start to tap his feet and you will hear echos as if he is standing on concrete floor and not in a dirt cemetery as his character is setup to be.
(at around 4 mins) When the robber with the ski mask points his revolver at Captain Spaulding for the last time you hear the sound of the hammer being cocked, yet in subsequent shots the hammer is uncocked.
(at around 1h 8 mins) In the graveyard scene with Mary, the shadow of the camera and cameraman can be seen as she spins around.