Factual error: There's a flashback to 1989 in an arcade and we see Mortal Kombat and Mortal Kombat II there. The original wasn't released until 1992, and the sequel in 1993.
Factual error: Like so many other films that take place underwater, this one makes the mistake of having characters who can hear each other underwater despite not wearing earpieces and having their ears exposed to the water.
Factual error: Towards the end, Quinn injects herself with a syringe full of Morphine to try and kill herself. She's dead in seconds. This does not act nearly that fast. Especially from injecting it in her arm.
Factual error: When they first get attacked in the mini van, the side windows crack and get scratches. (You can see the "spider webbing"). A side window shatters in small pieces when they crack slightly.
Factual error: Chucky murders his first (human) victim as he was taking down the Christmas lights, making him fall in the watermelon patch in front of his house. Shane must have an uncanny green thumb, to be able to have fully grown watermelons in winter.
Factual error: The scene where Pluto gets burned takes place at the Santa Cruz Natural History Museum, directly east of the Beach Boardwalk. In order to drive to the boardwalk in the scene immediately afterward, the Wilsons would have to pass through the line of Tethers holding hands.
Factual error: Parker is looking for the phone her mom hid. She is moving a box of cereals. The cereal ingredient label has a few joke entries you may Miss at first (goat hair, bitter almond paste, false eyelashes), but the nutrition facts tab is also incoherent in a way too subtle to be a deliberate joke; sub-categories of each macronutrients exceed the total. For instance, it has 5 g of Fat in total, but 25 g of Cholesterol and 56 g of Saturated fat (at most it could be mg). (01:00:25)
Factual error: She fires the entire magazine of a Glock into the alligator's mouth. When it is empty, rather than the slide locking back and the trigger freezing, there is an audible click every time she pulls the trigger. This could not happen.
Factual error: Laura, Aiden, and Mia often complained about how cold it was in the cabin. Mia kept her jar with the Sea-Monkey on her bedroom window sill - right next to the frosted/iced-over windows. The Sea-Monkey's habitat should not be exposed to direct sunlight and, more importantly, the Sea-Monkey needs to be kept in room temperature water or between 70-76° F (higher for hatching). Mia's Sea-Monkey could not survive under the conditions she kept it in at the cabin. (01:22:37)
Factual error: Bobby's shotgun hit blasts a hole through the head of the first zombie entering the store, but the zombie directly behind it, as well as the barricade, are unscathed. The shells can hardly penetrate this much, wide and clean through the head and then disappear with no trace. (01:35:05)
Factual error: After they get the key from the game, the lock they open is a modern Kwikset Smart Key cylinder.
Factual error: The Sheriff of the small town is wearing Sergeant stripes on her shoulder sleeves. If she was a Sheriff then no chevrons should be on her sleeves.
Suggested correction: Subtract 27 from 2019 and you get 1992. They were 12-13 in 92 so it is plausible that those games could have been in the arcade while they were still kids.
It's set in 1989, not 1992.
The "present day" scenes in this film actually take place in 2016, 27 years after the first film is set which would be 1989. The mistake is valid.
BaconIsMyBFF
Some of the flashbacks seem to be set after the first movie.
That flashback definitely was not supposed to be after the first movie, it featured Henry Bowers.
BaconIsMyBFF
And Pennywise would have been asleep in 1992~1993 so that whole scene after the arcade makes no sense.