Revealing mistake: Nearly at the end, the scientists find Alice's body at the waterfall, one of the men lifts up the cloth to take a look at her face. Her face is badly burned on one side and she is pronounced dead. However, take a look at the left side of her neck, you can see her either gulp or take in a quick breath of air.
Continuity mistake: After the gas explosion in the school, Angela reveals that Alice is infected. The woman cop asks "When were you gonna tell us that?" and the next shot shows Alice with burns/blood on her upper left arm. In the next shot as Alice goes to sit down, the severity and position of the burns/blood changes.
Continuity mistake: Watch the left side of the mouth piece in Alice's mouth when she is in the tank at the end. In the shot up close to her left there is a plastic support going up, in the next shot of her right the support is pointing down, and after the scientist says "can you hear me?" and the shot is close to her, the support isn't even there.
Continuity mistake: Toward the end, Major Cain storms aboard the helicopter, shouting "Why haven't we taken off, yet?" The shot switches to LJ (Mike Epps)in one of the pilot's seats. As he says, "Because I normally drive Cadillacs" he punches out at Cain with his left hand. In the reaction shot, however, as Cain flies backward, the punching hand is LJ's right hand.
Continuity mistake: When Alice and the group are going to raid the Umbrella guards and steal the helicopter, one of the men looks through binoculars with night vision. He looks at the helicopter, then looks to the right of the helicopter, yet in the next scene a second later, his head is in the same position as it was when he looked at the helicopter, before he looked to the right.
Revealing mistake: Near the end of the film when the zombies are shuffling up what looks like a parking ramp towards the escape helicopter, in several shots it's painfully obvious that some zombies don't have any makeup at all and a good portion are walking normally, unlike their shuffling comrades. One with blonde hair is even using a handrail.
Continuity mistake: When Jill Valentine and Angie are running from the dogs after turning on the gas, Jill kicks the left side of the double doors open. However, when she turns around to see if the match ignited the gas, she has the right door open. When Jill Valentine realizes Alice light a cigarette she starts running, again out of the right side of the door. (Looking at the doors from the kitchen to the cafeteria).