When Karl is talking to the Frostee Cream Boy, there are no cars on the road behind him. But whenever the camera is aimed at the Frostee Cream, there is a lot of traffic on the road reflected in the window. Billy Bob Thornton points out in the DVD commentary that this is because the local police had another pressing issue the day they filmed Jim Jarmusch, and they couldn't be there to stop traffic.
The morning after Karl slept at the warden's house the scene opens with an exterior view of a one-story house. The next shot is in the interior and shows a set of stairs that are obviously going up to a second floor.
When Randy, one of the guitarists, reacts to Doyle's demands to leave, Randy is seen from behind putting on his coat. However, when he walks out the door, the coat is draped over his arm.
When Karl is on Jerry's daughter's bed, the stuffed pig changes direction.
Frank goes down to the lake with Karl wearing blue dungarees. In the first shot, the buckle on his left shoulder is on top of his shoulder blade. Down by the lake, it's moved to much further back.
When Karl is at the Frostee Cream, if you look at the menu, you can see Blizzard's, Peanut Buster's and a DQ Sandwich on the menu board which would indicate that the movie was filmed at a Dairy Queen.
All of the items in Karl's father's back yard, namely the bed spring and tires, are spotless and rust free.
When Doyle drives to the county line to get more alcohol, they're in a "crew cab dually pickup," yet Doyle, Karl, and Vaughan ride in the front seats, the rest of the crew rides in the bed, and no-one rides in the back seats.
When Jerry and Karl walk up to Bill Cox's repair shop for the first time, the Steadicam operator's reflection can easily be seen in the right front hubcap of Jerry's car. He is visible during the entire shot, which lasts about 10 seconds.
Shadow visible in front of a tree when Jerry and Karl are walking.
The paper cap and name tag of the Frostee Cream Boy are misspelled "Frosty Cream."
When Karl and Scooter are looking under the "hood" of a push mower, Karl suggests checking the points. Lawnboys were two strokes and as such, had no points.