Continuity mistake: After the Zombies are unleashed in the desert scene, we see Carlos crawling under the truck. At first his semi-automatic gun seems to be completely normal. The gun's slide and chamber are closed as if there are still bullets in the magazine or at least one bullet is chambered. But then the camera focuses on his gun and we see the gun's chamber is open - as if there are no bullets left. The gun didn't fire between shots so it's chamber should have been open in the first place.
Continuity mistake: In the scene where Dr. Isaacs escapes from Alice in a AS350B Eurocopter, we see that the helicopter's landing gear has an additional iron bar that has been changed from one scene to another. When the helicopter lands in the desert, the bar is missing. So Dr. Isaacs flew away in one helicopter and landed in another.