Factual error: When Hank is let out of solitary confinement, he punches the guard. A prisoner would never have the chance to attack guards while in solitary confinement because he/she is cuffed while still in the cell. Also, there are always at least two guards for escort, not one.
Factual error: At the end of the bridge shoot out, Earl and Hank accidentally drive the van off the bridge and land in a garbage barge. This would not have happened, as at the time of this movie garbage barges were no longer used for transporting trash, to make LA a greener city. Mistake admitted to on DVD Commentary.
Factual error: Moments before Hank sees Charlie get shot, he tries to shoot through a window to get to him. The bullets have no effect, so he says, "It's bullet proof! I'm coming in!" He tries the door, and it's locked, so shoots the window again, having absolutely no effect. The glass would have at least cracked and shown signs of where the bullets were hitting. Even bullet proof glass is damaged by bullets. This glass was in perfect condition the whole time.