Revealing mistake: Luke points a flashlight along the side of the staircase, but no shadows are produced on the wall from the vertical posts. Luke points the flashlight in front of himself and produces his shadow on the wall behind (and the shadow doesn't look like the way he is holding the flashlight). After Luke goes through the entryway aiming his flashlight ahead, a circle of light is behind him. The power is out, so the flashlight is the only light source - except that used for filming in the dark. (01:03:00 - 01:05:25)
Continuity mistake: Leila places Stephen's wallet in the corner of the tray, practically aligned with both sides, but the wallet is at an angle when she places his keys on the tray. (There's no indication that she bumps the tray or wallet when she sets the keys on the tray.) (01:06:20)
Continuity mistake: Inside the building, Nina is at different distances from the man on the bench, ranging from about one body's width to a few widths away (while accounting for her limited movement). (00:15:15)
Factual error: April arrives for her first day of work at "Shady Oaks Senior Living" and sees Max, the resident who passed away the night before, being wheeled out on a stretcher with his head uncovered. A deceased person's entire body would be covered by the sheet. (00:03:14)
Continuity mistake: Ron (dad) brings Amanda her dinner. He carries a bowl approximately centered on a square plate. He quickly sets the plate on the table, so does not have time to adjust the position of the bowl. Ron walks away and the bowl is to the far side of the plate, and there are crackers filling the remaining space on the other side. (00:01:20 - 00:01:57)
Continuity mistake: Simi enters the bedroom and the upper half of the bedspread is smooth. Aunt Claudia is holding a book with both hands, so she is not touching the bed. The front (somewhat aerial) view of the bed shows that the upper part of the bedspread has multiple ripples. (00:17:55 - 00:18:42)
Continuity mistake: There are orange traffic cones about 3' from each side of the front bumper of Sarah's car, but they are not always visible when they should be. In the right-rear view of the car, the left cone is not visible, but the car cannot conceal it. The traffic cone is visible before Aden is walking around the front of the car, but not when he is walking to the door. The tip of a cone is visible some distance opposite the rear passenger door, but cannot be the one near the front bumper. (00:01:52 - 00:02:55)
Continuity mistake: Overlooking the sudden drop from 1:02 to 0:17 seconds on the countdown clock, the one-second interval beeps are not accurate. In the countdown from 10 seconds, there are approximately or precisely 10 beeps, then the countdown clock shows 4 seconds remaining. (00:19:55)
Continuity mistake: Stan (Grandpa) gets impaled in his upper left arm by the metal jack part. The front of his jersey's short sleeve is saturated with blood, almost to the orange stripe near his shoulder. Helen goes to see her dad's injury, and Stan's upper shirt sleeve and shoulder are free of blood, but the lower part and his arm are covered. (00:12:09)
Continuity mistake: The amount of Kyle's facial hair changes (i.e, grows too much/fast) from the beginning of the scene when he is on the rock talking to Jaelyn to the end of the scene when he is standing in the water. Kyle's facial hair is back to its lesser amount when he is in the villa; it isn't clear how much time has passed, but it doesn't appear to be much. (00:17:06 - 00:20:28)
Character mistake: The prosecuting attorney told William, "In the interests of getting this thug [Danny] off the streets as soon as possible, his attorney has agreed to plead guilty to assaulting an officer, possession with the intent to distribute, and resisting arrest, and that's all in addition to his parole violations. We're looking at five to seven [years in prison]." The parole violations alone are sufficient to get Danny off the streets immediately. (00:09:34)
Character mistake: We see the lead driving on the motorway to get to the cottage. She leaves at junction 6 for Princes Risborough. Which means she is on the M40 that goes to Birmingham. When she arrives the host asks about the drive down and mentions the M4. This is a different road entirely, that goes to Swansea.
Other mistake: At the end the camera bulbs would not work as they are electric. This is proven when the music starts after the creature leaves the area. (02:01:00)
Deliberate mistake: Abraham is sitting to the right of and slightly behind the cross he hammered into the ground, but is about 3' away. When there is a close-up, Abraham is much closer to the cross - the end of the crossbar to the right is directly above his shoulder and his knees appear to be close to the vertical bar. (00:45:15)
Factual error: The movie is set in the Northern Great Plains of the United States, and the tribe is identified as Comanche, but the Comanche were located in the Southern Great Plains, across present-day northwestern Texas, eastern New Mexico, southeastern Colorado, southwestern Kansas, and western Oklahoma.
Continuity mistake: Laura's hair was (flipped) above her shoulders when she brought Cody to school. When she was in her car, her hair was much longer, going at least a couple or few inches down her back. Laura's hair was back to its shorter length (above-the-shoulders) when she got to the typing room at work. (00:15:44 - 00:16:06)
Continuity mistake: The bite marks on Doc's sandwich were inconsistent/contradictory. Doc took a corner bite out of his sandwich, then the sandwich was shown with an additional side bite mark (made off-screen?). When the sandwich was shown again, the distinctive bite marks were gone and the side of the sandwich that had been eaten was straight across. Doc was holding the sandwich in his right hand; after another camera shift, Doc was holding the sandwich in his left hand and the unique side bite mark was back. (00:18:22 - 00:18:48)
Character mistake: Nolan said, "Everybody knows that no sharks swim in freshwater" and Spencer said, "They don't come into freshwater", but there are freshwater sharks (e.g, river sharks) and bull sharks (not true freshwater sharks) can survive in saltwater or freshwater. Jacob Harper (National Aquarium) pointed out eyewitness accounts of sharks swimming up the Mississippi River and "bull sharks have kidneys that recycle salt" but did not mention the glands near their tails that help keep salt in their bodies. (00:08:08 - 00:29:50)
Continuity mistake: When Joey is talking to Voight about the puzzle box and Voight tells him to "Keep going," pay attention. It's kind of hard to notice, but if you look closely, in the over-the-shoulder shot facing Joey, you can tell that Voight is standing straight, facing Joey before it cuts. When it cuts to the opposite angle, suddenly Voight's body has rotated about 90° (to his right).
Continuity mistake: The top of Brecken's head was close to (within a few inches of) the headboard before his mother brought the pillow. When his mother put the pillow over his face and the camera shifted to a right-side rear view, the upper part of the bed was raised about 45°. When Lang Dotrice (Brecken's father) arrived and sat on his bed, the pillow used to smother Brecken was at least a foot away from the headboard and Brecken's head (still under the pillow) was about a yard away from the headboard. (00:04:05 - 00:07:16)