Other mistake: The protected copy of the Bible is placed at the end next to a copy of the Artscroll Tanach which includes the Hebrew/English version of the original bible as well as the other 39 holy books, so they had it all the time.
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)
Continuity mistake: When Eli has the confrontation with the gang in the beginning he cuts the leader's hand off with his sword. When you see the sword in the very next shot, the blood is only on the edge of the sword and not smeared across it as it should be.