Continuity mistake: When Alice runs into the barn to hide from Pam, as she slides the door open, a plank of wood falls over, to the right of the door. In another shot of the barn, it is upright again. (01:17:00)
Continuity mistake: After Alice bangs at the lock with the end of the gun, the position of the lock and it's chains differs through the following consecutive shots. (01:17:50)
Visible crew/equipment: When Mrs. Vorhees throws Alice onto a table you can see a mattress under it catching her fall. (01:18:35)
Continuity mistake: After Alice hits Mrs. Voorhees with a frying pan, Mrs. Voorhees's arm goes from being by her head, to laying across her stomach. (01:22:30)
Continuity mistake: When Alice runs to the beach, there is only one canoe sitting there. But when she finally gets in the canoe and pushes off, there are two. (01:23:10 - 01:25:15)
Continuity mistake: Alice knocks the machete out of Mrs. Voorhees' hand, and we see it land. But when Alice runs and picks it up, it is in an entirely different place. (01:23:40)
Continuity mistake: Just one shot before Mrs. Voorhees's decapitation, you can for a split second tell Alice's hands are empty as she swings, and that she's not really holding the machete. (01:24:35)
Other mistake: After Alice wakes up in the hospital, watch the nurse after she gives Alice the injection. Her eyes, at one point, look directly into the camera. (01:27:45)
Continuity mistake: In the scene when Alice decapitates Mrs. Voorhees and Mrs. Voorhees raises her hands and grabs air, if you look carefully, the hands have hair on the back, even when, during the chase scenes, she doesn't have hair on the back of her hands. (01:27:55)
Revealing mistake: Toothpicks visible after Alice cuts off Mrs. Voorhees' head. (01:28:10)
Factual error: At the climax of the movie, Alice swings the machete at Mrs. Voorhees and decapitates her. When the blade makes contact with Mrs. Voorhees' neck, her head flies off at an incorrect angle, as though the cut began on the opposite side.
Revealing mistake: When Steve Christy is leaving the diner, it shows the outside of the diner, where it is raining. It's very obvious that the "rain" is just a sprinkler.
Factual error: After your head is cut off, you wouldn't be able to hold your hands in the air and make fists because your brain controls your ability to do this.
Suggested correction: Not really. There's such a thing as a death twitch. The a chicken's brain controls the ability to run, jump, and flap its wings, but it does just that after its head is cut off. A person could involuntarily clench their fists repeatedly when they've been decapitated.
You're comparing two different animals. The chicken with its head cut off that is still running around is still controlled by the brain. Part of a chicken's brain rests in the neck and when beheaded, it's possible not all of the brain is severed. This is not what happens to a beheaded human. There is a difference between a cadaveric spasm and clenching and unclenching your raised hands.
Revealing mistake: When the generator gets shut off they grab a couple of oil lanterns. However once lit you can see they are light bulbs.
Revealing mistake: After the girl escapes the moving truck, and stumbles through the woods, the killer catches up to her, and slashes her neck. It's obvious she's wearing a prosthetic, as it does not match her skin tone.
Revealing mistake: When Alice opens the pantry door to find Crazy Ralph inside, she is looking directly at the camera as if looking at him, but a second later she's looking to her left.
Other mistake: When Ralph is leaving on his bike he passes the same rock twice.
Character mistake: When Annie is in the red truck, she says that she'll be cooking for ten staff. When Alice goes to the beach, she tells Bill that everyone has arrived except for Annie. Even if she had arrived, there would only be eight of them: Christie, Annie, Ned, Brenda, Jack, Marcy, Bill, and Alice. Two shy of what she told the truck driver.
Factual error: There would be no slide latch on the inside of the pantry that Alice hides in before hitting Mrs. Voorhees with the frying pan. It would be on the outside.
Continuity mistake: When Ned fakes drowning he is a decent distance from the dock. When he is rescued he is much closer.
