Other mistake: The officers working at the Smith Grove Sanitarium have "police" on their uniform patches. When Michael Myers was boarding the bus to be transported to a different sanitarium the bus had a Corrections Department decal. Since corrections officers run prisons and jails along with sanitariums, the uniform patches should have said corrections, not police.
Other mistake: Nothing about Nedley Blake's interference in his daughter's morning routine at home makes remotely sense the way it is shown. It takes him 18 seconds (with cuts) to do something that needed to be made in the 6 seconds it originally takes Daphne to come down the stairs, and the first time around he was also shown arriving from the kitchen, which would further expand the time needed (considering also that the second time he apparently dropped the tray, causing rattling noise that Daphne should have heard). Not only that; the playlist action (which is something her computer science mother could have easily done with actual software, especially given the level of tech available to every teen in the movie) takes twice as long too, and at the end of it he exits the frame from the wrong direction - he should have headed left, because he needed to get into the closet to pass Daphne the proper clothing posing as the automated wardrobe.Sammo
Other mistake: At the end of the movie Lorraine has to remind Elise that she helped her once, implying they haven't seen, or spoken since. When Elise first meets Josh in the 1st insidious she tells Josh that her and Lorraine have been friends for a long time, implying they talk or see each other regularly.brianjr0412
Other mistake: Constantine is driving along a road and an big rig truck is heading for him head on. The truck honks and they both hit the brakes, stopping just a foot away from each other. But at the speed the truck was moving it could not have possibly stopped so quickly. It would have skidded into Constantine's car. (00:35:00)Quantom X
Other mistake: When Boyce and Ford are watching Chloe and the Nazi officer through the floorboards, the former are in the attic, the latter downstairs in the living room. Surely looking through the attic floorboards would only allow a view into one of the bedrooms. How then do Boyce and Ford manage to see down into the living room?
Other mistake: During the murder in the stairwell, an old woman opens her apartment door outward, and Varg kicks it shut. Apartment doors always open inward, as did Euronymous' apartment in the same building.