Continuity mistake: In the film Ted is at the bar with Paul and Ginny and Ted is flirting with the waitress behind the bar.The waitress has her wash rag slung over her right shoulder. The scene then cuts to a frontal shot of her and now the dish rag is now slung over her left shoulder. (00:52:10)
Continuity mistake: When Sandra and Jeff sneak off to Camp Blood they walk right along the waterline with the lake on their left, yet after crossing the barbed-wire fence, the lake (in the background) is on their right; this was a mirrored image.
Continuity mistake: When Paul and Ginny leave the bar, there is a faulty, unlit small headlight on the front left of the car. When they get back to camp the light is fixed and working. (01:01:00)
Continuity mistake: Jason drags Vicky down the steps all bloody, yet doesn't leave any blood on the steps.
Continuity mistake: When Jason enters the cabin you can see an umbrella. Yet when Vicky comes in, she's using that same umbrella. (01:01:35 - 01:03:50)
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 Jason comes smashing through the window at the end, to attack Ginny who is getting up from the cot, the camera angles are inconsistent with the attack. First he is lounging at her from behind, to grab her. Then his distorted face is suddenly at her left shoulder before he's even touched her Then she's looking back at him and screaming before his hands even touch her and pull her out of the window. (01:24:20)
Continuity mistake: When Jason takes the spear, he tosses the mask down, on the fifth step up. Later, when Vicky goes upstairs, the mask is on the sixth step up. (00:59:25 - 01:01:50)
Answer: Probably from inside the building he was standing in front of.
lartaker1975