Continuity mistake: When the Apes are trying to break into the mutant's church, Mendez looks towards the Alpha/Omega bomb, and is wearing a cream-colored jumpsuit with a purple sash. When the Apes do break in, his sash has disappeared. (01:25:50)
Continuity mistake: When the police catches the pickpocketer at the beginning, they literally lift him off the ground. There is a close-up shot in between, and the lack of continuity is apparent in the hand position of the man. Not just that: vehicles obviously disappear and appear in every cut.
Factual error: During the scene where Clint Eastwood is trying to convince Don Rickles to join in the heist, there is a box of Almond Joy candy bars behind Don's head. They weren't introduced until 1946. (00:28:50)