Visible crew/equipment: As Wes steps out of the shower and is drying his hair, you can just see the reflection of the camera man in the glass on the right side.
Visible crew/equipment: When Mia first does the ritual, you can see the boom mic on the bottom right corner. It hides in the dark corner, but if you look carefully, you can see it come in the shot. It's easier to, depending on how dark your screen is. (00:20:40)
Other mistake: During the dinner Slowik reveals that his restaurant does not have nor serve bread of any kind. Towards the end of the movie Margot requests that he make her a cheeseburger, which he does. Where did the buns come from?
Suggested correction: I just watched through the scene. The chef never once says that the restaurant has no bread. He only states that the guests will not be getting bread as part of this specific meal plan. Furthermore, we actually see a plate of bread at the start of the course, the dude-bro customers ask for bread since they know the chef has it, the notecard specifically discusses the bread that was made at the restaurant but won't be served, and another customer actually even specifically notes that the restaurant is known for their high-quality bread. Every single indication is that the chef absolutely has bread and is simply withholding it due to the theme of his dinner that night.
Suggested correction: He didn't say they didn't have bread. He stated THEY wouldn't get bread for that evening, since it's a common man's staple, and they are not the common man. So, they get a breadless bread plate with nothing but dipping sauces.
Factual error: The teacher sends her pupils to the woods to collect chestnuts. Later we learn that the date when all this happened is May 30th. Chestnuts ripen in autumn, around September-October. (00:52:18 - 01:05:06)
Continuity mistake: Before taking Michael's mask, Corey calls Allyson and tells her to meet him at the diner at 9:00 pm. Later we see Allyson at the diner waiting for Corey, but when she checks her phone and sees Laurie is calling the time is 5:36 pm. (01:13:56 - 01:24:41)
Continuity mistake: RJ got into his van and drove parallel to the house, almost reaching the end (right side) of the house when he saw Pearl in front of him and stopped. When RJ got out of his van, it was parked near the beginning (left side) of the house that he had already driven past. Also, Pearl was standing in front of a fence, so it didn't make sense that RJ would be driving straight toward a dead-end. (00:57:07)
Character mistake: After Dimitri put Leena's wrist bands on for her (through the door slot), Leena said, "I want to do something nice for you; you can come in." Dimitri agreed, and Leena pulled up a chair to stand on (to be his height) and caress his face/ hair. When Leena bent in to kiss him, she banged his head against the wall several times, killing him. As a "Saarne Instituute" security member, Dimitri should know not to get sexually involved with or trust a patient, especially the most dangerous one. (00:10:29 - 00:11:29)
Character mistake: Laura is on the floor, screaming and exhibiting bizarre behaviour, so Dr. Rose Cotter goes to the wall phone to call for help. Instead of maintaining observation and continuing an evaluation of Laura, the psychiatrist faces the wall while making the call and even stares at the wall for a couple of seconds after hanging up. A patient's body language can/do help make a diagnosis, so the psychiatrist should keep her eyes on Laura. (00:11:20)
Continuity mistake: When Maren is reading the letter her mother wrote for her, in a close-up shot of the letter, her right thumb is beneath the letter and her right index finger is above the letter. In the next shot, her right thumb is on top of the letter and her right index finger is beneath the letter. (01:22:24)
Continuity mistake: Ava sees the stack of mail on the table. She sweeps her hand (fingertips and envelopes are off-screen), as she slides the top envelope closer. Ava picks up the top envelope, as if her hand sweep does not move any of the envelopes (and serves no purpose). (00:05:48)
Continuity mistake: As the SUV pulls off alongside the curb, there are trees with orange-coloured leaves on both sides, but the leaves are green when the ladies are talking in the stopped SUV. The leaves from the tree that is about 15' from the curb are right outside the passenger-side windows. (00:10:15)
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)
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)
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)
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: 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: Jenna takes one red cup from the 3 stacked next to the higher stack and returns the two cups to her left (and left of the higher stack). Jenna uses her left hand, supported by her right, to handle the bottle of wine, but the 2 cups disappear after she sets the bottle on the table. (00:19:50 - 00:20:14)
Continuity mistake: The monkey figurines (or charms) on the beads hanging from the rearview mirror change positions from being more horizontal (side-by-side) to vertical (one below the other, and at different distances). Swaying from the SUV's movement might explain some change, but the weight of the monkeys should have kept their positions more balanced (side-by-side or one at the top and the other at the bottom). (00:03:30)
Plot hole: Mike carried Sophie into the hospital and walked through the halls yelling, "I need a doctor" until he ran into Sophie's Dr. Thomas. Sophie was put on a cot and rolled into a room where Dr. Thomas immediately began examining her. Mike completely by-passed registration, triage, etc, which wouldn't be tolerated at an emergency room. Emergency rooms are highly likely/almost always back-logged with patients, many with urgent conditions yet still might wait hours to be seen by a doctor or nurse. (00:06:45 - 00:07:20)
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)