Revealing: After Dr. Lawrence cuts off his leg and is crawling towards the gun, if you look at his dismembered leg, you can make out the shape of his foot hidden beneath his ripped up slacks.

Continuity: When Larry is desperately trying to reach for the cell phone, he uses the box that it came in. When that doesn't work he throws it off to the side (his left) but when we see it again the box is back where it originally was (on his right).

Continuity: When Adam pounds on Zep with the toilet seat, he grabs his shoulder in pain. In the first shot of him holding his shoulder, his hand is soaked in blood. In the second shot, however, his hand is much cleaner.

Continuity: When Alison gets the gun from Zep and aims it at him, the gun is in her left hand. In the next shot it's in her right hand, and then it moves back to her left hand again. This is not an artifact of changing camera angles, you can clearly see the different hands holding the gun.

Revealing: When Adam is searching Zep for the key to the chain once he has found the tape recorder watch Zep's tummy - he's breathing.

Visible crew/equipment: After the first call when Dr Gordon gets on the cell phone, a boom mike shadow is visible on the bathroom door.