Factual error: The type of book that Eli is protecting would actually be just a fragment. The complete Bible, in braille, occupies as many as 18 volumes.
Factual error: Eli uses an apparently moist KFC wetnap to clean himself in an early scene, yet it's been at least 30 years since the apocalyptic event happened. Unopened wipes only stay moist for months, even big packets of baby wipes only stay wet for 2-3 years.
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 is leaving Carnegie's town, as he walks away from Carnegie and his gang right before the shoot-out, the position of their shadows alternate drastically between shots, falling sometimes in front of the characters and sometimes to the side.
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.
Suggested correction: If the cutting took ages, there would be enough blood to cover the blade. The action was over very quickly though so no reason to expect there to be a lot of blood.
Plot hole: In one of the last scenes when the scribe is putting the newly published bible on the shelf you can see next to it a big green book with the word Tanach written on it. That is actually a translated bible with the Hebrew and English, including the five books of Moses and psalms plus much more. He had the Bible the whole time. (01:47:50)
Suggested correction: From the internet movie database... The Hebrew Bible, or The Bible or "the Chumash" in Hebrew, is already in the library. The Christian "Old Testament" is the Chumash with some variations (reorder of books and reorder of the 10 commandments, depending on religious denomination). The New King James Version is an Old Testament with the Christian Gospels added at the end, some of which the main character, Eli, quotes. These two books would be considered separate and unique in a library.