Continuity mistake: When Elise is being interviewed in the hospital by the detective, the way he's holding his pen instantly changes between shots as we cut from outside to inside the room.
Continuity mistake: After Specs kills Ted, we see Elise being interviewed by police outside as Mara is taken away to the hospital. Depending on the camera angle, sometimes Elise has police lights reflecting on her face, and sometimes not. It changes instantly between cuts several times. There are a few other minor continuity gaffs with the police lights throughout the scene as well.
Continuity mistake: When Specs kills Ted by pushing the armoire onto his head, when it crashes down, a huge crack forms in the side of it. The crack is missing in every subsequent shot of the armoire.
Visible crew/equipment: When Elise and Tucker open the hidden door, in the closeup of Elise, you can faintly see set-lights reflecting in her and Tucker's eyes. The the room in front of them is totally pitch-black, so there's no other light source that could be creating these light reflections.
Continuity mistake: When Tucker takes the hidden door from Elise and finishes opening it, he goes from holding it with one hand to both hands instantly between cuts.
Continuity mistake: When Elise uses the key to open the hidden door in the basement, her left hand suddenly appears on the door instantly between cuts. (It wasn't there in the previous shot).
Continuity mistake: After Elise returns to the basement with the keys, Tucker is holding his flashlight above his shoulder. It then cuts to a closeup of him, and he raises his flashlight above his shoulder a second time.
Revealing mistake: Normally I wouldn't consider a bad CGI effect to be a mistake, but when Elise finds the hidden keyhole in the wall in the basement, the effect is comical if you pay attention. The way it appears as she scratches is pretty unnatural, and the pieces of paint that fall practically look like cartoon pieces if you pay attention. The shadow of her left hand also looks a little too sharp compared to the rest of her (somewhat softer) shadow, revealing it was likely rotoscopped in some way.
Continuity mistake: When Elise is communicating through the wall by asking yes-or-no questions and getting responses via whistle, in the shots facing Elise, she's staring forward directly forward. But in the shots facing the wall, her head is turned sideways and pressed up against the wall. This happens instantly between cuts at least once.
Continuity mistake: When Elise and Tucker go down into the basement and hear the whistle, Elise approaches the wall. As she does, her right arm is bent up by her abdomen. When the camera cuts, you can see from her shadow that her right arm is instantly now down by her side.
Continuity mistake: When Elise and Tucker go down into the basement, they hear the whistle and Elise spins around in shock. Between cuts, she instantly goes from holding her flashlight above her shoulder, to holding it down by her chest.
Continuity mistake: During the second night of the investigation, after Tucker and Elise hear the whistle, Tucker opens the door. The shadow his hand and microphone are casting on the door changes positions between edits when it cuts to the POV of him grabbing the doorknob. (First it's on the door, then off).
Continuity mistake: During the second night of the investigation, after Elise and Tucker hear the whistle, Tucker starts to walk forward with his microphone. It cuts to an aerial shot of Elise standing, and you can see Tucker's feet, and he's suddenly standing still before taking a step back, despite the fact he was walking forward in the previous shot. He's also moved forward about 4 feet between cuts.
Audio problem: At the start of the second night of the investigation at Ted's house, Elise says "Why did you say 'help her'? Help who?" While the camera is focused on Tucker with the microphone, you can see Elise's face at the bottom of the frame and her mouth is not moving at all.
Continuity mistake: When Elise and the group are setting up for the second night of investigating Ted's house, Elise says Christian reminded him of the red door. The way she's holding the paper in her hands changes instantly between shots. She goes from holding it at an angle to holding it vertically, and her hands slightly change positions on it.
Continuity mistake: After Elise meets her brother at the diner, she breaks down crying and says she was "stupid to come back here." Specs responds by saying "No you weren't, you're helping people..." Specs' arm goes from down by his side to touching Elise's shoulder in a reassuring manner instantly between cuts.
Continuity mistake: When Elise meets her nieces at the diner, when Melissa says "it's really nice to meet you," the direction Imogen is facing changes instantly between cuts.
Continuity mistake: When Elise's nieces enter the diner shortly before they first meet, they walk by Elise. The shot cuts to another angle, and suddenly her nieces walk by Elise a second time. (You can tell from the shadows that move over Elise).
Continuity mistake: When Elise flees her house when she's 16, Christian follows behind her, calling for her. Suddenly, as Christian reaches the bottom of the stairway outside, their father Gerald appears right behind him. This is impossible... Gerald was nowhere to be seen in the previous few shots of the stairway, and furthermore, it was shown that he was walking with a cane and moved slowly as a result, so he wouldn't have been able to catch up to them that quickly. He just sort of... magically appears.
Continuity mistake: During Elise's flashback to when she was a teenager, she grabs her father, pushes him against the wall and makes him have a vision. However, his position on the wall changes instantly multiple times between cuts. Ex. First he's to the left of the painting on the wall... then the right. Then when he falls, he instantly lowers about a foot between cuts. Etc.
