Devon's hair changes lengths from scene to scene. This is due to the long delays between filming days throughout production.
A few of the police cars noticeably say METAMORA POLICE on the side of them.
During the window breaking scene, you can see that duct tape is holding on the false glass on the truck window.
You can see a white Dolly track reflected on the glass in the chemistry lab.
The reflection of a camera operator can be seen in the front door of the house as Devon stands up to talk to Stan.