In the Chicago sequence, Jimmy and Jagger are chasing one of the white supremacists through town and they pass the same man twice.
When Mister Keyes fights the corrupt police officers, his shoes go from brown boots to brown basketball shoes and back between shots.
The blue van alternates from shot to shot between two very different models.
When Jimmy is talking to Wendy from the phone booth he is clearly inside the booth while the gravel truck is charging the booth (0:54:04).Yet,seconds after the gravel truck hits the booth Jimmy isn't inside the booth and he is hanging from the back of the truck instead(0:54:09).
At the shoot-out around the dam site, the scenes go from being at night to night-for-day shots and back again. (What appears to be snow is actually concrete covering the rocks to prevent erosion around the dam.)
In the opening scene, two of the "dead" men are very visibly breathing or moving.
When Mister Keyes is fighting the cops in the street, there are already sets of skid marks on the pavement in the exact same spots where two different police cars skid and slide sideways to a stop - from a previous take, evidently.