Phillips's deal happens in the middle of the night, but within twenty to thirty minutes it's already mid-morning.
In the first scene, just before Dillon starts his motorcycle, the gag is around the hostage's neck. But when Dillon gets to him, the gag is back in his mouth.
When he first meets the Sheriff near the end of the movie, Flick's beard is significantly shorter than it appears just a few minutes prior.
When Flick meets Amy near the end of the movie, Flick hits Amy. He is wearing his glasses before striking her yet immediately after hitting her, they are gone.
When Dillon is carried to the boathouse for execution his hand are tied behind his back but when he jumps in the water to escape suddenly his hands are tied in front of him. (Had his hands remain behind he couldn't have cut the tie.)
During the shootout in the boathouse, the muzzle flashes don't match the gunfire sounds.
When the SUV "crashes" in the woods, the "dust" thrown up by the crash is visible slightly before the crash happens.
In the opening frames of the film, the black cars are just sitting in the middle of the desert. They only start moving once the camera gets closer.
As Dillon leaves the first scene on his motorcycle, several tire tracks are visible. While one could logically be the track he followed to get to the scene, the others must be from previous takes.
After leaving the boathouse, Dillon fires the first gun he obtains without cocking it, meaning there was one round in the chamber. He is then unable to fire again because the magazine is empty. Why would a guard be on patrol with a completely empty magazine?
Before leaving the boathouse, he makes no effort to take the bad guys' weapons or search them for more clips. That character would have been more resourceful.