Continuity mistake: During the final chase scene where Melanie Kinnamin is running through the woods the pink sweater which is over her shoulders disappears and reappears at random, until she finally loses it by the tree where her co-worker is found murdered.
Plot hole: When the cop shows Pam the newspaper clippings they include what look to be fresh photos of the real Jason from the events of Part IV, yet no photographer is ever seen taking pictures of Jason alive in the previous films and most likely wouldn't live long enough to publish the photo.
Plot hole: At the end when Tommy is in the hospital, he gets out of bed and goes over to the drawer where his belongings are. He opens the drawer and there's the mask the killer was wearing. How did it get there? The police should have taken that as evidence. There is no way that police would let Tommy keep this mask for a souvenir.
Continuity mistake: We see Vic outside the halfway house, just starting to chop a 4-foot log with a double-bit axe. In the same scene a few moments later, as Joey approaches, Vic has chopped about a third of the way through the log. Problem is, it's a completely different log (different shape, texture and color).
Plot hole: When the couple go into the woods to have sex, after they finish, the guy goes to a pond to clean up, which is not very far from where he left his girlfriend. A couple minutes later, "Jason" is about to kill her, and she screams very loudly. Despite this he doesn't hear her.
Continuity mistake: When Reggie hits Roy with the tractor, the wound on his chest only appears after he has hit the ground.
Continuity mistake: Just before Junior is killed, the level of the stew Ethel is making changes from shot to shot.
Continuity mistake: After Reggie's grandfather flies through the window, his head changes positions between shots. We can also see that he is breathing, even though he is dead.
Revealing mistake: When Anita lies dead on the ground with her throat slit you can see her pulse in her neck.
Revealing mistake: When Sheriff Tucker shows Pam the newspaper clippings taken from Roy's wallet, plainly two of the columns in the article are identical and have nothing to do with Jason.
Continuity mistake: In the film Joey has chocolate on his face/left side of his mouth. The amount of chocolate changes on his left side as he is walking off the porch towards Violet.
Continuity mistake: In the film Demon is in the outhouse and is sitting on the bowl when it begins to shake. The toilet paper changes amounts on the roll between shots.
Continuity mistake: In the film Tommy tosses the alien mask that he wore to scare Reggie on his bed and the mask slides down the wall and is all crinkled up. In the following shots Tommy takes out another mask and you can see the alien mask now laying flat on his bed and away from the wall.
Continuity mistake: The sound that startles Lana was breaking of plates. But when she investigates, she finds the cat sniffing fallen pots.
Continuity mistake: In the film the killer.aka."not the real Jason" is seen walking through the rain soaked grounds and woods , but yet when he climbs up the ladder at the end of the film his shoes are pretty clean.
Revealing mistake: When Ethel gets a cleaver in her face, blood spatters everywhere. Yet the cleaver blade is still clean.
Visible crew/equipment: As Pete walks off into the woods, the cameraman's shadow is briefly visible on his back.
Revealing mistake: When Jason is raising the machete above Tommy in the woods, it's obvious that his eyeholes are covered with black cloth. This also happens at the end of the movie, where Tommy hallucinates about Jason in the hospital.
Continuity mistake: When Violet is dancing in her room, Jason starts to walk up to her and we see the knife has dried blood on it. Then he picks her up, stabs her takes the knife out and now the knife is clean.
Revealing mistake: When Tommy goes to slice Roy's arm, you can see he is not really holding the machete in his hand.
Factual error: When Vic is in the police car, there should be a screen separating the front from back seats.
Revealing mistake: After the "Friday the 13th" logo explodes, the supports that were holding up the model are briefly visible through the smoke.
Continuity mistake: Lana smears lipstick on her upper right lip, but when she turns at the cat's noise, it is pressed and perfect-looking.
Continuity mistake: In the scene where Jake gets a cleaver smacked in his face, you see him get slashed across his face. When Robin goes to bed and she sees him die, you can see the slash on his face is in the opposite direction.