After the robbery, Doc and Carol's blue car plows through a neighboring porch. The windshield is clearly shattered by one of the broken porch columns. As soon as they are out of town, the blue car is immaculate.
In the train station, when Carol discovers that her locker key has been switched, she is holding the key for locker number 090. Shortly after she hands it to Doc, the locker number on the key is 249.
During the bank robbery, the same couple walks past the main entrance twice.
The gray Mercury driven by Carol at the drive-in hits at least one other car head on, yet in later scenes the nose is intact.
When Carol and Doc open the station locker and they realize that the grifter has stolen their money, Doc's jacket momentarily disappears only to reappear shortly thereafter.
In the opening scenes at Huntsville State Prison, the inmates are wearing white uniforms with black belts. Inmates are never allowed to have belts because they can be used as weapons (for strangulation).
The radio station from El Paso identifies itself as WHIL. Radio and TV stations west of the Mississippi River use call letters beginning with a "K", not a "W", which are found only in the east.
After the robbery, Doc meets Rudy at the barn. Doc fires a model 1911 pistol in .45 ACP at Rudy, but the recoil is unrealistic. A pistol recoil moves the barrel up and rearward. In this scene, Doc is pulling the pistol rearward only.
During the chase after the drive-in a crew member holding a camera is clearly visible in the front passenger seat as the car drives towards the camera.
While waiting for Doc at the train station with the money bag, there was no reason for Carol to put the bag in a locker.
Doc checks into the hotel. Given room 318 and told, "Nobody on the floor. You're by yourself." Yet later on when he clobbers Rudy over the head (who's standing outside his room ready to barge in) that starts Fran squealing wildly until he slugs her silent the camera cuts to a woman reading a book in bed. She lowers the book looking to her right, not up or down, indicating she's on the same floor and not in a room above or below the screaming commotion.