When Rainwood is in the bathroom drying his hair, his hairdryer is white. When he is shot by the David Rasche character, the hairdryer is gray.
At the end of the movie, when Parnell and Scalise are driving through the parking lot, looking for the drug pickup spot, the front license plate on their T-Bird changes. Initially it has a 2FVDxxx then changes to a 2GRYxxx.
The plexiglass piece used to make the shank is obviously much thicker than the rest of the broken window.
After he gets out of jail, Jimmie Rainwood's wife makes him a cup of tea. It faces different directions in different shots after he puts it down on the bookcase.
When Rainwood stabs the other inmate with the Plexiglas shank, he supposedly breaks off the handle. Yet, the pointed end is seen when Rainwood swings the shank to the side. In a later shot, the pointed end is missing.
At the end of the film, one of the bad detectives goes to prison and is marched into the middle of the general population. No prison in the United States allows former police officers to be sent into the main prison; such persons are always sent directly to protective custody.
When Jimmy shanks Jingles he is encouraged to break off the handle. While this might be good for evidence purposes, leaving a penetrating object in a wound is the number 1 rule as it potentially reduces blood loss. Jingles would be more likely to die if the blade was removed.
Rainwood is granted parole on his first appearance before the board, yet during his time in prison Rainwood was sent to solitary confinement twice for insubordination towards the Guard Captain and was also the primary suspect in the murder of another inmate. Based on the regulations used by the California Parole Board, it is highly unlikely that someone with Rainwood's prison record would have been granted parole.
When Jimmie arrives home the evening his wife passes her exam, Jimmie is clearly seen locking the door to his Camaro when the window is obviously down.
When Jimmy arrives home on the night of the bust, he closes his car door with the window down and then uses his keys to lock the car door. Locking the door using the keys with the window open is not necessary nor is it effective.