When Mary and Cassandra are helping with the Prom preparations, Patrick helps Mary fold a red banner, and her side is all crumpled. In the next shot when Patrick is holding it, it is folded perfectly smooth and flat.
When Roland is stranded at the school he sleeps in front of the giant Jesus billboard. In the morning he is shown laying on his back, on the ground, covered with his jacket. When he sits up seconds later, he is wearing his jacket.
When Tia is reaching for the receipt under Hilary Faye's seat her purse changes position from shot to shot.
The prom takes place in June, yet in the scene after Hillary Faye crashes into the Jesus billboard at the prom, you can see everyone's breath as if it is very cold outside.
After Cassandra is saved, the next day at school, at Hilary Faye's locker, Cassandra pinches Hilary's cheek. When Cassandra pinches her cheek, Hilary's sweater goes down from her face, in the next shot, Hilary's sweater is back up.
When Mary and Hilary Faye are painting the Jesus billboard in the opening scene, the break at Jesus' neck from when his head falls off later is clearly visible.
When Mary and Hilary Faye are painting the Jesus Billboard, you can see that there is no paint on their brushes.
When Mary enters Hilary Faye's van for the first day of school, her hair is especially curled at the ends for that first day look. When she gets out of the van to see why Dean's late, her hair is not nearly as curled.
Shots of trees with leaves that have changed colors appear throughout the early part of the film, yet it takes place at the beginning of the school year, presumably September. Fall foliage would not start that early in Maryland, where the film takes place.
When the Christian Jewels are performing at assembly, Mary's hands are not playing the correct piano notes and when she takes her right hand off, the high notes can still be heard playing.
When Patrick is on his Vespa scooter giving Mary a lift home, you can clearly hear the sounds of the engine changing gear, but Patrick's doesn't move his hands or touch the clutch of the bike between gear changes.
A sign visible in the background of one scene in the school lobby uses the spelling "honour", an indication that the school is actually Canadian.
The film is set in the US, but the drugstore that Mary visits is a Drugstore Pharmacy. That company only exists in Canada.
In the food court of the "Maryland" mall, extras seated behind the main characters are eating French fries from the fast food chain New York Fries - a Canadian company.
When Mary goes to the drugstore to by a home pregnancy test, she passes a stand of health-related brochures. The film is supposed to take place in the US, but was filmed in Canada. One of the brochures she passes is for the CNIB, the Canadian National Institute for the Blind.
As the main characters sit in the food court of the "Maryland" mall, the signature green sign of the company Grand & Toy is clearly visible behind Mary's head. Grand & Toy is a Canadian company.
Pastor Skip is willing to believe the charges on Hilary Faye's credit card could be anyone's, yet immediately accepts the signature on the credit card receipt is hers when it could easily have been forged.