Continuity mistake: In the opening scene, there are spectators and the camera zooms in on a man and woman with a Rottweiler standing next to the woman. There is a glimpse of two people past the dog. The camera briefly shifts to show a woman (Sonny) walking toward the front door, then returns to the spectators. The Rottweiler (presumably the same dog) is now standing near the left side of a different man (and is not next to the woman). (00:02:02)
Continuity mistake: The cat/pet door in Sonny's house looks worn (dirty and has paint chips), but in better condition (newer/cleaner and "boxier") when the cat ("Monster") is being pulled through. (01:17:52)