Plot hole: During the end the murderer is thrown out the front window of the building. The students leave the building through the front door, but yet there is no body, and that doesn't seem to bother them!
Plot hole: In one gruesome scene, the killer hangs Natalie's friend in the woods and then crashes a car into a tree. Natalie escapes and comes back with campus security (who didn't bother to call the police even though a murder had just been committed). When Natalie and the guard get to the murder scene, all evidence is gone. How did the killer manage to remove the body and all pieces of the car within ten minutes (not to mention somehow hide the dent left in the tree by the car crash)?
Plot hole: When Natalie and Damon are in the woods when Damon goes to the bathroom and the killer approaches him from the behind, it cuts to the scene with Natalie in the car. Then she gets out and sees the killer then runs to the car. You see the killer put rope on the car but how does the killer hang Damon without Natalie noticing?
Plot hole: When the girl in the car gets killed she is decapitated with an axe. All you see is her noticing someone in the back of the car then a shot of an axe coming through the driver's seat window. How did the killer manage to swing an axe in a car and take off someone's head whilst he was sitting right behind her?
Plot hole: At the end of the film, Brenda could not know that Nat and Paul were to drive the truck in order to wait inside it for them.
Suggested correction: Didn't Nat come there in that truck? And assuming the truck wasn't locked or lockpicking is amongst Brenda's veritable arsenal of skills, maybe she hid by the car until she saw them coming, and got in.
Plot hole: Brenda's shown to have survived at the end and is at a different college. This is never explained given she got shot, fell out a window, thrown through a car window and off a bridge into a river.
Suggested correction: Supposedly human killers surviving the impossible is a staple of slasher movies, though that doesn't really make this not a mistake. But people in real life have survived worse.