Deliberate mistake: When the kids are about to jump start the trap Phoebe hides behind the school bus door. Half a second later, when the trap opens, she's nowhere to be seen, not even jumping or stepping inside the bus. Then half a second later she has managed to get inside, turn around and protect her head while the bus windows burst. It all happens in real time for their hairs are still fluttering. It sure paces up the scene, but it's really awkward.
Other mistake: The van used by Cecilia to chase Tom should be damaged because of the crash, but it was not.
Factual error: The "hard suits" the divers wear have soft, relatively normal gloves and soft joints. More akin to a football uniform with armor over spandex. They are at the bottom of the Mariana Trench, at 36,0000 feet below sea level. The pressure is over 7,000 psi. Without a hard suit, they would instantly be crushed.
Continuity mistake: At the market, Lee picks out five pieces of fruit (one apple and four oranges?), tears a produce bag off, and walks away. He takes a few steps off-screen, and he is next seen going around an end cap and walking down an aisle, with nine pieces of fruit in the produce bag. (00:01:36)
Continuity mistake: SPOILERS: During the final scene, when Samuel L. Jackson is "puppeted" to lift his arm up to make it look like he's pointing a gun at the SWAT team, the number of laser-sights visible on his chest changes between cuts. In the wide-shot, there's only three, but when it punches into a close-up, suddenly there are five.
Continuity mistake: At the arena, when Scooby's blue suit bursts, the ground is covered in small blue pieces that disappear in the following shots.
Continuity mistake: The girl that wanted her bully in high school to be tortured filmed the torturing with an iPhone XR then was later holding an iPhone X before the movie ended.
Continuity mistake: The characters are on a tile floor that has one yellow tile visible among the black and white tiles. The next shot they're in a different spot on the floor with two yellow tiles visible. (01:22:10)
Other mistake: In the credits of the movie, the creator of the original comic's name is misspelled as "Bob Macleod" when it should read "Bob McLeod."
Factual error: The soldiers had 506 Regiment's helmet markings of the 101st Airborne, and on their sleeves the 82nd Airborne and 1st Division shoulder patches.
Continuity mistake: Look at the forehead of the hotel manager. Everytime he raises his eyebrows, you can see his prosthetic forehead piece.
Other mistake: The rectangular area of skin cut from the dead deer's rear side was not wide enough (or at the correct angle) to encompass the killer's entire bloody hand print; it would have missed the "pinky" finger (and possibly the tips of the second, third, and fourth fingers). Because the fingers were spread out, a shape more like an inverted isosceles trapezoid (or a much wider rectangle) would have been necessary. (00:42:52 - 00:44:09)
Factual error: Apex, played by Robert Maillet (a retired professional wrestler 6'11" and 350 pounds), forcefully slams Becky (played by 5' tall fifteen-year-old Lulu Wilson who probably weighs under 100 pounds) horizontally with her back hitting the ground from waist-high yet Becky is able to get up with no incapacitating injury that would be expected. Becky also manages to brutally kill him (as well as the three other neo-Nazis).
Continuity mistake: When Char begins chasing the car with Millie, Nyla and Josh, they are on an empty road and there are no other cars around. Instantly between cuts, they are suddenly on a different road, in a different area, and there are a ton of cars around. Char started chasing them almost instantly, so there's not enough time for them to suddenly be on a different road in a different area.
Continuity mistake: Yi-Na had her head turned to the right while her dad Sang-Won was talking to her from the front seat and, eventually, Yi-Na closed her eyes. After a camera shift, Yi-Na's eyes were still closed, but her head was turned to the left. (00:04:17)
Deliberate mistake: The images of Spencer's face in the driver's side mirror are not realistic for someone in the driver's seat. The driver's side mirror is angled outward (perhaps 60° beyond a typical angle), but his face is perfectly reflected. When Spencer starts smoking, the viewer gets a glimpse of a figure behind his car. Spencer senses something and his face is shown backwards in the mirror, as if he were crouching outside a few feet from his car. Spencer does not use the more practical rearview mirror. (00:19:11 - 00:19:47)
Continuity mistake: The amount and location of dirt on Christine's face is inconsistent, ranging from being very thick and obvious to barely visible, if at all. Sometimes it extends down her neck on the right side. When her hair covers most of her face, no dirt is visible - until she turns her head and the hair is away from her face. The intensity and location of the redness on her neck also varies. (00:03:31 - 00:04:48)
Character mistake: Tyler said, "Charlie says you're [Ben] gonna tell your folks that you got that girl pregnant this weekend." "This weekend" is a misplaced modifier. Ben didn't get the girl pregnant this weekend; Ben is supposed to tell his folks this weekend that he got a girl pregnant. (00:22:15)
Continuity mistake: Views of Michelle's car wreck were inconsistent. When the car veered to the right and was headed toward the tree, the driver's view showed most of the car was to the left of the tree trunk. On impact, it looked like the right side headlight hit the middle of the tree trunk. Michelle got out and a rear view showed the tree trunk roughly lined up with the steering wheel (i.e, more than half of the car was to the right of the trunk). After impact, both headlights were shining in front of the tree.
Continuity mistake: The amount/shape/size of the blood/cut on the bridge of Joey's nose varies, as does the obvious presence or absence of blood on the right side of his nose. (00:42:32 - 00:43:50)