At the beginning of the film a baby is born, and when there is a close-up of the newborn it has a bellybutton. A newborn baby would still have part of an umbilical cord, revealing the baby is actually older.
Towards the end when Kady and Amanda are escaping from the doctor's office and they turn and run behind the house, if you look closely at the bottom left you can see a brown bunny hopping away that the actors had startled. This is right before they are shown running across a bridge.
In the scene where the two local Police Officers sit in their side-by-side parked cars, in the dialogue between them, one of the Shot-Revers-Shots which visualize their discussion, one shot is reversed. The Police Officer who's wearing the Police hat sits - mirrored - in his car and it looks as if its a right-steering car. The patch on his arm shows letters which are mirrored too.
The lobotomies received by the townsfolk are administered through the back of the skull (revealed by the wound dressing), into what would be the Parietal Lobe of the brain, which controls sensory and visiospacial information. This is because the Greavers made revisions to the normal lobotomy procedure (as shown on the chart in the basement).