Factual error: Tony writes a "postcard" on the back of a picture to Adrian and Veronica to an address in Cambridge including the postcode. This scene occurs in 1967 (we see the date on the letter he is responding to) but postcodes weren't in use in Cambridge until at least 1970.
Continuity mistake: The protagonist is driving his diminutive car to the villa. In the view from the villa (Avishai Cohen's name pops up) you can see a large shadow covering the area of the gate. In the reverse shot that part of the road is fully lit. (00:06:00)
Continuity mistake: At the beginning of the movie, Bob Fredericks pulls his bicycle over. His wife takes off leaving him behind. A young man walks by him twice in the two separate shots and at different distance. (00:01:00)
Continuity mistake: Maggie gets downstairs while Henry and her daughter are playing with their phones. The hair goes in front and behind her right shoulder depending on the camera angle. (00:03:00)
Continuity mistake: When Saul and "Nookmis" (his grandmother Naomi) leave on the canoe, there are several blankets/rolls of food between them. The pile reaches to about Saul's waist in the canoe. When Saul and Naomi continue their canoe trip the following morning, the pile of blankets/rolls between them is higher (almost to Saul's shoulders) and the colors/sizes look different (larger, even though they obviously ate some food). (00:11:37 - 00:12:09)
Continuity mistake: Throughout the scene at Stukey's, when Helen Mirren is chatting the Syrians' ears off her elbow sticks out of the window at variable length between shots. (00:05:45)
Continuity mistake: Jake and Wendall are talking on the track field as they pull some weights. The strap attached to Wendall's glasses keeps moving in front and behind his shoulder between shots. (00:03:30)
Visible crew/equipment: When the police woman falls off the boat when the shark hits it, on the right side of the screen, you can see a hand outstretched, as if reaching out to grab her. It doesn't belong to the only other person on the boat, since he's behind the wheel and completely out of reach. So, it belonged to a person who wasn't supposed to be there.
Factual error: A group of people are traveling in a pickup truck escaping earthquakes and volcanic eruptions. They come across a mist that they identify as sulphur dioxide, mainly by its smell and effects on people. Then the plastic interior of the car starts to melt, and they attribute it to the sulphur dioxide. Sulphur dioxide can attack plastics and rubber, but only in its liquid form. It turns gaseous at -10° C. After that it is a gas. So the melting of plastic is not correct at ambient temperature.
Continuity mistake: "Lean on Pete" and the car were obviously repositioned after the accident. The car hit Pete on his left side/legs, Pete's back landed on the hood, and Pete continued to roll over the roof and fell on the opposite side. It took a few cars lengths' distance for the car to come to a complete stop. Next, Pete was suddenly in front of the car, lying on his left side, and facing the direction he was running before the impact. (01:28:51)
Continuity mistake: After the car almost hits Lenna and Dalton, they walk beyond the right corner of the car's bumper, but are still in front of the bumper when the camera shifts. (00:01:55)
Factual error: The musicians in the (real) Band of the Coldstream Guards that plays Happy Birthday for Christopher Robin are wearing their 21st-century uniforms and medals.
Continuity mistake: When Mariah is talking to the girls on the bridge at the beginning of the movie, the girl in green is holding her leash (her dog's that is) with her right hand in the shots from behind, the left hand in others including the wider ones from the protagonist's height. (00:02:25)
Continuity mistake: After Danielle stabbed Junior, his papers were by his feet. When Junior's mom found him, the papers were by his hands. The knife was also closer to his feet compared to when Danielle dropped it onto the floor. (00:03:39 - 00:04:30)
Character mistake: Set in Texas, the Sheriff threatens the wrongdoer with the gas chamber. Executions in Texas at that time were all by electrocution, namely by "Old Sparky," the electric chair. Texas has never used the gas chamber for executions.
Plot hole: Henry gave Principal Wilder reasons he believed Christina was being abused: "Bruises, exhaustion, decreasing school performance." When Susan confronted Glenn near the treehouse, she said, "I know what you've done. Emergency room visits, school absences, bruises..." Neither had any concrete evidence/proof. Emergency room visits should have resulted in detection or suspicion of abuse if that's what doctors or nurses believed, and they are among the mandatory reporters. Maybe Henry was wrong. (00:20:35 - 01:30:30)
Continuity mistake: During the fight, a stop sign is ripped off a bus and thrown to the ground. It disappears in the next shot.
Character mistake: In the highlighted newspaper article entitled 'DeFeo Son Accused' about the killings, the first sentence of the article ends with two periods. Also, in the 3rd sentence, the word 'psychiatric' is spelled "psuchiatric" with a 'u' instead of a 'y'. (00:01:05)
Other mistake: The private investigator has a full size Glock. The Glock 21 which is a .45 ACP has the lowest magazine capacity of 13 rounds. The 9mm capacity for the Glock 17 is 17 rounds. The PI exchanges gun fire and after he fires 7 rounds, his gun runs dry. Makes no sense to bring a half empty gun to a fight, plus he just got it back from his brother-in-law. (01:05:00 - 01:06:00)
Visible crew/equipment: When Detective Hole enters the murderer's cabin you can see somebody running in the snow outside.