Revealing mistake: The guy with the sunglasses changes from behind and in front of shots. (00:09:46 - 00:10:15)
Continuity mistake: The amount of snow accumulated on the chalet's wraparound porch railing was higher when looking outside compared to external views, such as when Emily was outside talking on the phone with Becca. (00:13:35 - 00:15:05)
Plot hole: After sending the offensive message to his students, Charlie got on-line with them (within hours or the same day?) and said, "Well, your complaints have been heard. I've been replaced..." IF an on-line college instructor could be terminated and replaced as quickly as Charlie was, it would follow that he would no longer be able to access the on-line course to communicate with the students like he did. (01:39:55)
Suggested correction: I think this is based on too much assumption. Any sort-of ban would likely be entire dependent on whatever system they're using for their online class. And it's entirely plausible he'd still be able to access his account mere hours later, even if the call has already been made to replace him.
I worked for the Defence department in Australia and it was a running gag that eighteen months after I had left my online access to my account was still open, allowing me access to highly classified documentation, including emails. Mistakes happen.
Continuity mistake: During the time Sean and Kunle are talking to Bianca after class, Sean is wearing two gold necklaces but only the longer one is showing a few times. (00:04:30 - 00:05:41)
Revealing mistake: The size of the spider walking off Sam's face becomes disproportionately smaller too fast compared to its size while on her cheek plus the spider's awkward movements are indicative of CGI. (00:02:20)
Continuity mistake: The sky (sun versus clouds and color - blue, white, or gray) changes frequently during the few minutes when Lara is leaving the site until she returns to retrieve her bag. Before she falls into the hole, the sun is shown near the horizon, about to set, but the sun is shining on her in the hole. A setting sun would not be able to emit rays into a distant hole. (00:05:34 - 00:10:15)
Continuity mistake: After he exits the limo, the Black Mask's entourage man with the long hair has the briefcase handcuffed to his left wrist. When he is walking up the steps, he is carrying the briefcase in his right hand, until he stops halfway up the steps and the briefcase is handcuffed to his left wrist like it was. (00:03:25)
Continuity mistake: Outside the warehouse door/metal gate, Shae's flashlight produces a bright circle of light onto the pavement because it is a dimly-lit area. She uses her flashlight to look under the gate, which is open about 2' at the bottom. After she rolls under the gate, the pavement now behind her is in the sunlight. (00:42:15)
Other mistake: Virgil drives the truck across flat land, yet the dashboard and A/C unit atop it are angled at about 45°. Views of Keith in the passenger seat show a level/horizontal dashboard and A/C unit, like they should be. (00:17:12)
Continuity mistake: Dan and Allen were close together when they were talking on the dirt road. Based on how far Allen threw the blindfold toward Dan's feet, Dan's feet/boots should have been visible. The blindfold was close to Dan's feet in the wider shot. (00:15:13)
Continuity mistake: Ishmael shots Karim in the right side of the stomach, but the wound moves to the left side.
Continuity mistake: Solomon put the rope around his waist underneath his coat, but when he was walking through the woods the rope was tied over his coat. Also, the knot would start out in the front of his left side but change to behind his back even though the rope was loose (not taut) behind him. (00:01:55 - 00:02:26)
Continuity mistake: At the start of the movie when the guys are arguing on the porch the guy on the ground suddenly appears to be off the porch in the next shot on the ground.
Continuity mistake: Young Norma Jean is shown a photo of her father placed at the head of her bed. It has him facing right and there is a large white defect in the photo at the upper left corner. When the photo is "talking" to her in a succeeding scene, he is facing left, and the defect is on the upper right corner.
Continuity mistake: When Harry wrapped Lily's ankle injury, there was bloody wrapping below the duct tape. When Karl asked to see Lily's leg, there was no blood showing on the material below the tape. Also, Harry did not completely cover the ankle injury with duct tape like he did to keep creatures from smelling the blood on Lily's stomach cut, questioning why the creatures could not smell the blood on Lily's ankle. (00:19:55 - 00:26:50)
Continuity mistake: While Ben is talking to Eloise, his glass of alcohol is about three-fourths full, but when he lifts the drink to his mouth, his glass is almost empty. (00:07:20)
Continuity mistake: The white car in front of the Mustang is parked along the edge of the driveway/pavement when Flynn gets a gun out of its trunk, but is parked partially on the grass when she drives the Mustang around it. (It appears as though the Mustang was moved to the right of the screen). (00:26:54 - 00:27:38)
Deliberate mistake: There is one vertical board missing between the other parallel boards, but the upper half of the gap is wider and forms a "V" when Mark is videotaping Jenna (who is on the other side of the fence). The missing board, between two parallel boards, has a uniform width from top to bottom. (00:08:40)
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)
Revealing mistake: A white truck could be seen in Tamra's rear window, following her car at varying distances. After Tamra hit Randall on his bike, the white truck was still there but gone when the camera returned to a front view of Tamra. Use of a green screen - the truck could not have gone past the accident or "disappeared." (00:03:35 - 00:04:10)