Continuity mistake: In the first shot of the dead man hanging form the tree, his head appears to be about 12" from the tree limb. After Mattie climbs up to cut him down, his head is several feet from the tree limb.
Continuity mistake: When Solara hijacks the SUV after leaving George and Martha's, there are mountains that disappear from shot to shot. Right after Carnegie yells "Go back," you can see mountains in front of them. When Solara gets out and looks at them turning around, those mountains are gone. After she grabs the grenade and stands in the middle of the road, they are back. When she throws the grenade and Carnegie's vehicle swerves out of the way, the mountains are gone again. (01:27:30)