Continuity mistake: When the girls have the trucker follow them, they are shown sitting on top of the car. However, when the driver is walking up to them, they are shown getting on top of the car again. (01:50:22 - 01:50:51)
Audio problem: When Thelma approaches the Highway Patrolman's window you can hear her cocking the revolver she then points at his head, but the revolver remains visibly uncocked.
Revealing mistake: Near the end, as they are chasing the two women, the cops turn around on the freeway into the dirt median. They follow exact tyre tracks from previous takes.
Audio problem: Right after the girls blow up the tanker, there is a sequence with scanner traffic. They show some helicopters. Right at the beginning of the scene with the choppers, the audio of them cuts out for a split second.
Revealing mistake: When they blow up the tanker and drive in circles around the truck driver, the ground has been disturbed from previous takes.
Chosen answer: It's just as you said; he was telling the others to hold their fire. He had no idea that they were going to drive off the cliff; his reaction was evidence of this.
zendaddy621