Continuity mistake: When Ana finally escapes in Peter's truck, the truck is a Nissan Frontier extended cab with a long bed, no tonneau cover and no roof rack, but shortly after they show her crossing a bridge in a Frontier crew cab (4 door) short bed with a tonneau cover and a roof rack. It is also has dirt on the side that looks like road salt whereas the original truck was very clean. (01:16:00)
Continuity mistake: Dr. Stone mentions there is an emergency exit below the landing pad. He then asks the pilot if there is a camera underneath. In this shot, the pilot has his eyes partly closed and his lips pursed together. It cuts to a close up of him and suddenly his expression is different, with his eyes wider open and his mouth open. (00:19:50)
Other mistake: The movie is said to be set one year after receiving Annabelle, but the music box from The Conjuring is on the shelf. Judy in The Conjuring is an 8, possibly 9 year old whereas in this film she celebrates her 10th birthday. If Annabelle Comes Home" is only 1 year after obtaining the doll (2 years prior to The Conjuring timeline) then Judy would not be turning 10 years old; she essentially lost a few years of life rather than vice versa.
Continuity mistake: At the ATM, when Ramona is pulling money out, you can see the reflection of a police car pull up behind her. It pulls up just as she begins to turn around and nobody is getting out in the reflection nor are lights on. But suddenly when she turns around several officers are already standing with guns trained on her and the lights on.
Continuity mistake: Right after the scene where Nels saws up his gun, he walks into a store with his arms folded. His hands are down close to his stomach. When it cuts to the next angle, they are much higher at his chest. (00:26:51)
Continuity mistake: After the wolves have killed the guy poorly sniping them at the old encampment location, Clair Hamilton glares at Larsen from her sitting position and moves towards him to ask more about what he just said about Father. During this sequence, Gina Carano's hat is burdened by a bit of snow or practically no snow at all, back and forth with no logic between cuts. (00:35:50)
Character mistake: Detective Spitzer went into Harper's dark/unlit house, saw his partner Greg on the floor, and then saw Alec standing in the kitchen. Without identifying himself, telling Alec to drop his weapon (pistol pointed toward the floor), or bothering to determine what happened, Detective Spitzky shoots Alec. (01:27:08)
Other mistake: While in the pool room, Zoey falls off the wall onto a portion of floor that hasn't collapsed yet and loses consciousness. This area is next to the section of floor that collapsed first. Jason jumps down to help Zoey. As he is helping her up, and onto the wall, that section of floor collapses, forcing him to grab the wall to avoid falling 20-ish stories with the floor. As he looks down drop, the section of floor that fell first is amazingly back intact. (00:59:20)
Continuity mistake: After Brandon finds out he arrived in the alien craft, he walks outside in the rain where he finally translates "Take The World" as his purpose. He continues on to Caitlyn's house to tell her what he has discovered and to give her a flower. When he arrives in her room, he is completely dry.
Continuity mistake: After the kids are told Sara hung herself at the hospital, Chuck asks "what are they waiting for, let's go". Stella is bending down to pick up the book in one shot, but the angle cuts while Chuck is still saying the word "go" and suddenly he has vanished from the room as the other two start to leave.
Character mistake: Toward the end of the film, Detective Davis orders Captain McKenna to put his badge on the table. New York City police always refer to their "shields", not badges.
Plot hole: Dr. Seager told Beth that "It [Z] was all in her head" and only she could stop it. How, then, did her son Josh have the same "imaginary friend Z"? Moreover, if Beth had Z as a friend when she was eight years old, why didn't she remember him or have her memory jogged when Josh first told her about his friend Z? Also, if Beth told Z that they would be together forever (get married and have a lot of kids), why would Z need to go through Josh to get to her?
Factual error: She fires the entire magazine of a Glock into the alligator's mouth. When it is empty, rather than the slide locking back and the trigger freezing, there is an audible click every time she pulls the trigger. This could not happen.
Character mistake: Right at the beginning of the movie, introductory technobabble. "In this canister, there's a solution of protons. The canister is attached to a rotor circuit that generates the protons to the speed of light." I believe the science genius and creator of time travel mixed up the words "generate" and "accelerate" here. (00:00:50)
Continuity mistake: Throughout the movie in several scenes the living room has 2 couches even up until the Parks are getting ready to leave for their camping trip, 1 big one and one small. The very next scene when the Kims are getting drunk, the small couch has disappeared. This must be to make room for the Kims to slide and crawl out from under the table. The strange thing is when the Parks come back home, they don't notice that one of their couches is missing. It remains missing until the end.
Plot hole: So when he travels through time whatever he has on him or with him or whatever he's holding goes back in time with him just like his dog or the wood. Now he's sitting on the rock drinking a beer and his friend is talking to him and all that's heard and seen is his beer bottle breaking on the rock when he disappears through time. Makes no sense for it to fall from his hand and break if he's in possession of it. The beer should've gone with him. (01:26:30 - 01:27:30)
Continuity mistake: After Wesley has intimidated the snot bully, he comes back home and finds the police. Sitting at the table, his mom holds his arm and says "Wesley, Mr. Chambers asked you a question." Mary Elizabeth Winstead has her right arm on the table, close to her body. Change of angle and she is holding the coffee mug instead. (00:45:10)
Continuity mistake: When the guy leaves the motel, he only grabs his jacket, but when he's outside, he has a helmet in his hand. (01:14:55)
Factual error: Attorney Aegis inappropriately rounded up/down a couple common statistics pertaining to the infamous Ford Pinto case, which resulted in a total that didn't add up: "it would cost the company $11 per Pinto to fix the problem. But with 12 million [should be 12.5] of 'em on the road, that would cost $137 million compared with $50 million [should be 49.5] to maintain the status quo. $137 million to fix a $50 million problem..." But 12 million x $11 = $132 million [not $137 million]. (00:24:38)
Factual error: The Sheriff of the small town is wearing Sergeant stripes on her shoulder sleeves. If she was a Sheriff then no chevrons should be on her sleeves.