When Tatum and Boot are talking in the Minosa's back room, the amount of alcohol Tatum pours in his glass changes.
When Chuck meets the sheriff for the first time and sits down with him, he puts the cigarette in his mouth twice as the camera changes; in the same shots, the sheriff's arm changes from the palm of his hand being on the table to his forearm leaning on the table.
When entering Mr. Boot's office at the beginning of the movie: The folder and newspaper in his left hand change position between cameras from outside and inside the office.
Rattlesnakes will not eat bubble gum, in or out of the wrapper.
Between when Tatum tells everyone to leave and when he comes out of the store, there is no time for the cars of several thousand people to leave the area, let alone strike the tents, dismantle and remove the carnival, remove all the wiring, etc.--and pick up all the litter.
When Tatum and Herbie walk out to their dust-covered car after all the people left, handprints from where Tatum leans on the car can be seen in the dust indicating that they shot the scene numerous times and decided to put one of the later takes in the movie.
When Lorraine and Chuck are talking out in front of Minosa's store by the gas pumps, reflections of the crew moving around behind the camera can be seen in the store windows.