Continuity mistake: At the prison visiting "Uncle Sally", Dickie sets a box of matches on top of his cigarettes. A little later, the matchbox is behind the cigarettes and the cigarettes are angled about 45° more away from the ashtray. (00:48:12)
Other mistake: Rebecca electrocuted the giant sand worm within 3' of the spaceship. After Lt Astrid arrives, some views show Rebecca out in the open, but the camera should have been obstructed by the spaceship because following front views still show Rebecca next to the spaceship. Also, at least part of the dead giant sand worm probably should have been visible at times but was not. (00:51:55 - 00:52:20)
Factual error: The Channel 5 WNP Newscaster said, "it is now believed he [District Attorney Berdido] and his family were killed..." and running along the bottom of the screen was "4 confirmed dead in Fort Lauderdale gas explosion." This was a LIVE report showing two streams of water onto the house still burning inside. An investigation would barely, if at all, be started at this time and no-one would be "confirmed dead" this early. It would not even be known if anyone was home when the house exploded. (00:04:34 - 00:04:55)
Continuity mistake: Leonardo DiCaprio's phone is shown attached to his car dashboard. He gets out of his car, all the while, looking up toward the sky. The next scene shows him grabbing his phone from his pocket while standing outside his car. (01:36:06 - 01:36:56)
Revealing mistake: The possessed "Helen" that Fr Daniel threw to the ground by grabbing the back of her hair landed like a stuffed doll, not person. The "body" was mostly padding and the fake "Helen" kind of bounced or teetered after hitting the ground. Also, her arms stayed hidden in front of her whereas a real person would be stretching out or moving arms to try to land as safely as possible. (00:21:35)
Character mistake: Immediately after kissing (through masks) and having close contact with JJ, Valeria removed her protective mask and went to check on her sick/crying child. Valeria was clicking her tongue, kissing her child on the face/head and putting her hands around the child's ears/hair. Valeria did not take appropriate preventive measures for contracting and/or spreading COVID-19. (00:18:40 - 00:19:29)
Factual error: Morse code is supposedly being transmitted by the blinking street lights. They supposedly spell "For 3veryth5h1ng that 7iv3s is holy." I know Morse code. It was just a random scattering of letters. (01:00:05)
Continuity mistake: Mia holds her doll's face next to hers, but the doll is not there when the camera shifts. The doll is to Mia's side on the bed, but instantly back next to her face. (This is independent of the times Mia moves her doll.) (00:02:25)
Other mistake: At the Night Driver gallery showing, Haley is reading from a program that describes Anthony's "Say My Name" piece. The text states that Helen Lyle died from "self-emulation" instead of "self-immolation", immolation meaning death by fire.
Revealing mistake: Based on the size of the dinosaur's back shown behind the 6' high cement enclosure, there is not enough room for the rest of the dinosaur's tail and the enclosure is not high enough to accommodate its neck and head. (00:16:29)
Factual error: Sassoon's Military Cross medal is shown ending up thrown in the Mersey and sinking. In his own words from "Memoirs of an Infantry Officer", published in 1930 - "I ripped the MC ribbon off my tunic and threw it into the mouth of the Mersey. Weighted with significance though this action was, it would have felt more conclusive had the ribbons been heavier. As it was, the poor little thing fell weakly on the water and floated away as though aware of its own futility."
Factual error: James called the "Washington Board of Psychiatry" to file a complaint against Dr. Clark (Philip). Complaints (which need to be WRITTEN) against medical doctors are filed under a State's Medical Board, which would be the Washington Medical Commission in this case. Washington has a Board of Psychology and there is a Washington Psychiatric Society, but there's no "Washington Board of Psychiatry" per se (and even if there were, a complaint would still be filed with the Medical Commission).
Factual error: It isn't known how long Tommy's mother was dead (overdosed), but Tommy told Parker that his mom and dad had been "asleep for hours." When Parker felt Tommy's mom's neck for a pulse, her body appeared to be stiff. Even if rigor mortis had not set in, it would take more than Parker lightly passing his hand over her eyes to close them. Parker didn't even really look to see if his hand was over her eyes when he gently passed his hand over her face. (00:02:35 - 00:03:35)
Revealing mistake: When Julie is running around the city whilst all the extras are stood frozen, there is a moment where she is walking next to a small park, before beginning to turn right and run down a road. Once she runs onto the sidewalk after running down the road, two girls can be seen stood on the same sidewalk holding hands. The girl on the right can be seen moving her right hand ever so briefly, even though the extras are all supposed to be standing completely still. (00:54:35)
Factual error: During the escape from the farmers market a red London bus is in the background. Those busses aren't used in Gloucester.
Other mistake: While Snake Eyes is fighting at the beginning of the film, the other guy throws him to a block of concrete. Snake hits on his head and should be dead by then or at least seriously injured.
Audio problem: When Russo drives off in his Tesla, you hear the car revving and gear-shifting, despite being electric. (01:04:58)
Other mistake: Narrating, Ringo said "Let me be clear. I never steal from people who don't deserve it." He was in a bank's safety deposit room, which was full of hundreds (if not thousands) of safety deposit boxes. Ringo was selecting specific boxes from among those along the wall, but he couldn't know whose boxes they were. (00:02:44)
Revealing mistake: When "Snowball" is sleeping on Lena's bed, it is obviously a "stuffed double" (stand-in). Snowball is usually partially hidden behind the dog (so breathing doesn't need to be shown/mimicked). The failure of Snowball to make even a slight movement is a giveaway (e.g, no ear movement when Lena starts talking), but even the stuffed lion, in itself, is not a very good replica - it simply looks fake. (00:33:44 - 00:48:20)
Factual error: After Ressler tells McChesney he wouldn't be surprised if one day she's tracking down sequence killers, McChesney replies, "Not sequence killers. Serial killers. That's what they should be called." But it was Ressler who claimed he coined and is often credited with coining the term "serial killers" (at least in the U.S). ** After showing pictures of some of Bundy's victims, Ressler is shown and it is pointed out, "He [Ressler] is credited with coining the term 'serial killer'." (1:31:30). (00:26:40)