Chase tells Pogue and Caleb that he heard they were swimmers while the pair are playing foosball at Nicky's, but his mouth doesn't quite match up to the words, almost as if he's yelling it and then it was voiced over.
Before the dance, there is a shot with Caleb's mom and Reid (Toby Hemingway) is in the background. For a split second in the background, Reid bumps against the stuffed leopard and then awkwardly tries to adjust it.
In the last scene when Caleb raises his hand to mend the windscreen, just as the windscreen is mended near his raised hand, his hand rises again from the bottom displaying the 'millisecond' overlapping mistake of the film editor.
When Sarah, Kate and Chase are returning to the dorms after the party from the beginning of the movie, Kate's hair is in front of her shoulders. In the next scene, when Chase knocks a spider off her shoulder, her hair is already pushed back.
In the scene where Sarah is in the library, Kate comes and leans on the table next to her. When we first see her close up, her ponytail is dangling by her head, it zooms out and the ponytail is on her back, again it zooms in and is in front of her face, zooms back out and it's on her back again.
While driving Sarah to his family's first settlement house, Caleb points out the Old Putnam Barn. While they are driving it is not raining, but during the shot of the barn it is raining pretty heavily (probably due to the weather during shooting). The next shot is back to normal with no rain.
In one of the classroom scenes, the instructor states that of the first 12 amendments proposed to the US Constitution, 10 were "eventually" ratified. In fact, 11 have been ratified. The 27th Amendment (originally the 2nd proposed amendment) was ratified in 1992, more than 2 centuries after it was written.
When Caleb is driving, before he sees the graveling and has the accident, he is on the left side of the road. There was no one else shown on the road, so he wasn't passing anyone, which means there is no reason for him to be on the wrong side of the road BEFORE he was frightened by the image.