The character of "The Reader" is called "Herbert" by Cody in a scene in their cell and by his lawyer during a conversation in the visitors room. Yet when Evans is listening to the police radio broadcast giving the names of the convicts who escaped with Jarrett in the prison break, The Reader's name is given as "Michael Curtin".
When Cody is in the shoot-out with the Police towards the end of the movie he is up high on a platform. Just before he shoots his revolver he closes his eyes and flinches before he pulls the trigger on his gun.
When Pardo is in line to get his injection, he starts a fight to get off the line and avoid being recognized by Bo Creel. But starting the fight draws more attention to him than if he'd remained quietly on line, and increased his chances of being spotted and identified. Also, the inmate giving the shots was looking at the arms of those on line, not their faces, as they moved passed him.
When Cody, Velma and Ma duck into the drive-in theatre to evade the police, the film showing is TASK FORCE which Ma Jarrett also states was the movie playing when questioned by the police the next day. However, a close look at the marquee on the drive-in theatre reveals that the film playing is SOUTH OF ST. LOUIS.
In the last scene after Cody and the gang try to escape the refinery (after the Police presence has been made known), the day to night continuity during the escape/shoot-out scene changes far too fast. After a Police character says ..."Get some search lights", the film goes straight from noticeable day-for-night photography to actual night photography.
In the opening scene the crooks are riding in a late-1940s Cadillac limo. Cadillacs of that vintage had standard rear fender skirts. As the car approaches us we see its left side and the left fender skirt is in place. Then the car goes around a bend and we see the right side. There is no fender skirt on the right rear fender. But a few seconds later the car arrives at the railroad track and stops right on the track. We're looking at the right side of the car and the fender skirt is in place as it should be. The two scenes may have been shot on two different days. Very trivial, of course, except for old car buffs.
In the machine shop, after Parker decides to drop a motor from an overhead crane onto Cody he moves the scrap metal barrel to the middle of the aisle. There is scrap piled toward the top of the barrel but in the next shot of the barrel it appears empty with no metal showing.
The police, planning to travel from Los Angeles to a state prison in Illinois, would probably have planned to fly to Chicago and not Springfield. The envelope sent to Vic / Hank only says "state penitentiary, Ill.," but they probably would have been in Joliet or Pontiac, both in NE IL.
When Cody is ventilating the car trunk for Parker, he is using a Colt 1911A1 pistol. When he runs out of bullets, the gun clicks when he pulls the trigger -- on a 1911A1 when the magazine is empty, the slide locks back and pulling the trigger does nothing - that doesn't happen with Cody's gun.
In the shot looking toward the ceiling of the prison machine shop, showing the piece of equipment Parker plans to drop on Jarrett supposedly dangling directly over Jarrett's head, it is clear that the object is in fact well to the right of Jarrett (from his perspective), undoubtedly a precaution by the filmmakers so that it would not accidentally fall and hit actor James Cagney (Jarrett).
After the train job at the first hide-out, some of the gang is gathered around the 1947 Cadillac 75 limo listening to the radio news about their caper. A shot of the interior shows a chrome "Cadillac" script on a plate above the radio speaker grille. This plate must be removed when a radio is installed as this is where the dial, controls, and push buttons are located. Since the plate is still present, it means in reality there is no radio in the car.
After the prison break, the men are in their cabin hideout when the phone rings. Cody gets angry and rips it off the wall with several violent tugs yet the wire never moves. Once the phone comes completely loose, it's apparent that the phone was never hooked up to the wire in the first place.
As the camera pans the Los Angeles skyline before dissolving to the inside of Evans's office, it is broad daylight. But when the scene dissolves to the office interior, where Evans is interrogating Willie the informant, it's suddenly dark outside as seen through the window, and all the lights in the room are on, further indicating it's night. Subsequently, the scene shifts from the interior of Evans's office back to the L.A. skyline, and once again it's daytime. Also, the skyline shot of the buildings shown after this office scene is obviously a freeze-frame, as the flags are frozen in mid-flutter and there is no other movement visible.
Near the start of the film, Big Ed and his thug pal hold the conductors hostage and direct them to stop the train when they tell them to. When the conductors are put out of action, Big Ed (Steve Cochran), pulls the emergency cord himself to stop the train, showing here was never any need to get the conductors involved at all.
When Ma Jarrett is shopping for strawberries and is seen, the detective leaves the store carrying a bag of produce. It is difficult to determine whether he actually takes the bag into the phone booth with him, but there is nowhere outside the booth to place the bag, but there was a shelf inside old phone booths. Either way, when he exits the booth he no longer has the bag, and as soon as he ties the rag to the car bumper, he walks down the sidewalk, away from the booth where the bag may have been left.
When Cody drags Verna back into the hideout to "get" Big Ed Somers, he deliberately rings the "alarm" bell which Ed has installed on the front door. After the shots are fired and Cody's gang rushes through the door, the bell is silent.