Goofs

When Dr. Burns fires the pistol the second time, the slide locks back. In the next shot, however, the slide is again forward.

When trying to move the ceiling tiles for the first time, she needs the extra height of the door handle. The second time, she is able to reach with just the bed.

When they first show the doorknob in the room, you see the heads of the screws and the small hole in the middle of the knob. This is backwards, as the screw heads are always on the side with the locking mechanism, otherwise anyone with a screwdriver could escape a locked room. The door also has the hinge pins on the inside, meaning anyone with a hammer or prying mechanism could escape by simply removing the pins from the hinges.