Continuity mistake: When Jen's head is on the floor you see the view from her attached camera is facing Sara, Rudy and Jim but when you see Jen's head on the floor the camera is in a position where it is facing straight at the floor. (01:01:25)
Continuity mistake: Halfway through the film, we see Michael Myers walk into a room immediately followed by another Myers. Both are dressed nearly identically in a blue jumpsuit. But as soon as the first one turns around and we learn it's actually Freddie, the shot changes to Michael and back to him and he's wearing his jean jacket, seen in the rest of the movie.
Continuity mistake: Near the end of the film, Deckard is communicating to Sara's handheld device where Michael Myers is in the house. When Deckard tells Sara to "GO NOW!", the text has changed from small digital text to large bold font and the screen has changed from green to white, similar to a large PC monitor.
Continuity mistake: Freddie has all the cameras cut when they find out he's a fake Michael Myers. When the kids complain to Deckard about it suddenly going offline, they tell him to bring it back. Deckard types at a fast rate, yet not only is there no dialogue box for text to be typed in, the screen remains the same.
Continuity mistake: Nora picks up her phone twice before she makes the call to Freddy in the garage, whilst Charlie is getting killed.