In the final stages of the film, the Jack and Quentin are holding pistols at each other crossed at the wrists, Quentin's pistol repeatedly switches from his right to his left hand throughout the scene as they argue verbally.
The green hospital door is not locked, otherwise the handle wouldn't move; it actually opens.
In the final scene, Candace drives while Jack is in the back seat of the car. They discus that "maybe there are some leap year babies in the next town over" yet there are multiple vehicles passing their vehicle on the road, and much traffic seen in the background. For a town that is not supposed to have any rational people, they have too many background cars following traffic laws for the plot to stick in this scene.