Visible crew/equipment: As the camera moves in on the shower curtain when Alice is taking a shower, you can see the shadow of the camera. (00:08:35)
Deliberate mistake: At the beginning, Alice turns on the tea kettle and it starts whistling less than a half a minute after it's turned on. It'd take alot longer. (00:10:00)
Revealing mistake: When Alice moves toward her window with the ice pick and the cat jumps in, it's obvious a crew member threw it in. (00:10:40)
Continuity mistake: As their car is towed, the guy hangs up the phone and it remains on the hook. When it cuts the phone is hanging off the hook, as they are running from the phone booth. (00:15:00)
Continuity mistake: When the girl who owned the dog is hit in the bum with a slingshot, she is hit in the right butt cheek, yet she grabs her left butt cheek. (00:19:00)
Continuity mistake: After Scott hits Terri in the bum with the slingshot, he holds the slingshot up by his shoulder. In the next shot his arm is down by his side. (00:19:05)
Continuity mistake: When Ginny shows up at the campgrounds late, as she gets out of her car to go speak with Paul, she pushes the driver-seat sunsheild down. After their talk, she goes back to the car and the sunsheild is up. (00:20:35 - 00:21:55)
Continuity mistake: When Ginny promise to Paul that she never will be late again, Paul puts his arm around Ginny over her shoulder. When it cuts his arm is lowered. (00:21:30)
Continuity mistake: When Scott is dancing with the dog, in the shots from inside the cabin, the collar on his shirt is up. But from the shots outside the cabin looking in, his collar is down. (00:26:50)
Continuity mistake: When Scott is dancing with Muffin the dog, Muffins little bow is dark blue. But through the window shot, her bow is bright purple. (00:26:50)
Continuity mistake: When Ginny puts on her red robe and fixes her hair in front of the mirror, some of her fringe is sticking out. When it cuts her hair is hanging down perfectly. (00:28:35)
Other mistake: Right at the part where Crazy Ralph is looking in on Paul and Ginny. Ralph hears a breaking of a stick behind him. You can see Jason put the barbed wire up and over the tree. How is that possible? He would have to whip it around the tree, not over it. (00:30:20)
Continuity mistake: When the two kids are heading for 'Camp Blood' they get to a fence with a sign reading "No trespassing". The boy puts his foot on the right side of the sign pushing the fence down. When it cuts his foot is on the left side of the sign. (00:35:35)
Audio problem: When the band starts to play the guitar solo doesn't match the guitar player's fingers or picking. (00:41:10)
Plot hole: When the counselors are dividing up who is going into town to the bar and who is staying, Paul tells them only a limited number can go because there are only two cars. They leave in a little bug-looking car and a pick-up truck. Then, when the girl is freshening up for the guy in the wheelchair, she goes outside to what is presumably her car, searches the front seat, and finds the hair brush she is looking for. I guess technically, there are only 2 cars and 1 "truck" but the truck is the other vehicle that goes into town, so presumably he meant 2 "vehicles" which would be incorrect since a 3rd was obviously left behind. (00:42:15 - 00:57:15)
Continuity mistake: When Terri is undressing to go skinny-dipping, she changes out of her clothes and her hair is dry. In the very next shot, she is entering the water and her hair is moist and slicked back. (00:44:25)
Other mistake: When Jason sneaks up behind the cop and raises the hammer to whack him, the angle shows it aiming for the cop's neck, but in the continuing shot, he strikes the back of the cop's head. (00:45:35)
Continuity mistake: When Terri is walking back to the cabin to get a knife, her pants are untied at the waist. When she reaches the cabin, they are tied with a bow, yet when walks back to Scott, they are untied again. (00:47:45)
Visible crew/equipment: When Terri is back at the cabin looking for a knife, she crouches down giving us a clear view of the mirror. Look closely, you can see a crew member carefully moving in the right side of the mirror. (00:48:00)
Continuity mistake: When Jason slits Scott's throat, he slits straight across, yet the wound is diagonal. (00:48:25)
Answer: Probably from inside the building he was standing in front of.
lartaker1975