When Patrick and Reign fight Amber in the bathroom they trigger a foam fire sprinkler that completely soaks them with water and foam. When they go find Rory on their next scene their clothes and hair are completely dry.
One scene Rory is strapped to the bed, then he had both arms free to break "Junk Man's" neck, then he was strapped to the bed again.
After Brad hits father Conway with the car they stop ,but then briefly as they yell you can see them still driving.
The mysterious girl at the film's onset play's Quarantine's music on vinyl before her self-inflicted death. They only released digital versions of their music.
There is neither an "F" nor a "Z" on the Ouija board. There also isn't a "0", though there is a "10". However, given the state of mind the characters are in, this may be intentional.