Corrected entry: Brenda weighs about 120 pounds. How is she able so often through the film to overpower men almost twice her size, hang them from trees (Damon's death) and then drag the bodies up to the top floor of an abandoned building? All without any help. Surely someone would notice a waif-like girl trying to drag a 200 pound body through the campus. When you are crazy then you suddenly have superhuman strength?
Corrected entry: Not really a mistake, just something that bothers me. Why would you cut someone's head off while they are driving fast? Since the decapitation kills the driver, and the murderer is in the backseat where she cannot control the SUV, wouldn't this cause the SUV to crash, possibly killing the murderer as well? By just looking at how fast the SUV was going when the girl was beheaded you'd think it would at least hit a tree or go over an embankment.
Correction: Actually the driver hits the brakes when she notices the figure in the back seat. So the car stopped moving.
So the killer should have been thrown into the front or through the window.
Correction: Actually, yes. People on an adrenaline high can accomplish physical tasks that would otherwise be impossible. However, there's also the fact that Brenda has spent years planning this revenge - presumably she built up her muscles over that time. Just because she's not bulging doesn't mean she isn't strong.
Shay