Deliberate mistake: During the rumble scene it's raining and everyone gets wet and muddy. Right before the Socs surrender, we see one of the Socs whose clothes are completely dry and clean. He's wearing a light blue shirt.
Suggested correction: That was to show he was the toughest of the Socs' group and that no one took him down. This was not part of the book but a choice by the director.
Deliberate mistake: When Cochran sabotages the Jet Ranger helicopter by loosening the nut on the bolt securing the linear actuator governor, the bolt is inserted in the wrong direction. The bolt should have been heads up to prevent it from falling out as it did causing the helicopter to crash. Moreover, the linear actuator is on the opposite of the engine from where Cochran disconnected it. (00:38:05)
Deliberate mistake: When Cletus is driving the Trans Am as the bandit, it shows him driving to the left and waving at a group of girls. The close up of him driving must be reversed because it looks like the Trans Am is now a right-hand drive. (00:26:45)