Continuity mistake: In the shot of the horse jumping off the ferry, the ferry's name "Quinault Seattle WA" is seen on its side. Rachel looks down at the horse in the water from the same place it jumped, but the appearance of the ferry's name is now different, namely the position of the two words "Seattle" and "Quinault" are now flush with each other when they were not before. (00:55:40)
Revealing mistake: After Rachel tumbles down the well, we see her heavy-duty Eveready Commander Flashlight, 12-volt battery and all, bobbing above the surface of the water like a cork. Which is ridiculous. A real 12-volt Commander Flashlight would sink like a rock, because it weighs about 4 pounds. However, the filmmakers needed to explain how Rachel could see at the bottom of a pitch-black well, so they used a lightweight, floating flashlight prop, supposedly providing a light source for the scene.Charles Austin Miller
Continuity mistake: In the first scene in Rachel's apartment Noah bites into an apple. First we hear him say 'ok' while he is still chewing but it doesn't sound as if there is something in his mouth, then he goes on talking after swallowing down everything, and finally we see him from behind, busily chewing again without having taken another bite. (00:29:30)NancyFelix
Continuity mistake: The scene where Aidan is waiting for his mother in the classroom starts with a close-up of his hand drawing a sun. From the way the rays are arranged we can tell that it's not the same drawing that's used in the later shots. Similarly, the picture his mother takes out of the folder later is not the same she is looking at when the camera angle changes. Also the way she holds it is different. (00:07:20 - 00:09:05)NancyFelix
Factual error: The well in the video is situated on level ground. The Cabin under which it is now supposed to be has been constructed on inclined ground.
Continuity mistake: When Rachel enters the reception at Shelter Mountain Inn the caretaker asks her to pick a card from a deck. She picks the nine of diamonds, but when she gives it back to the guy you get a blurred glimpse of the card, and it is a four of something. (That she finally agrees that the seven of spades is the right one is probably because she gets tired of the game.) (00:21:15)NancyFelix
Factual error: In the scene where Rachel is walking in the street looking at the photos she has just collected from the photo-shop, her hands (and the rest of her body) are moving in the natural way. In the shot at the photos taken from behind her you can see the ground moving underneath her but her hands are perfectly stable suggesting she is standing on a moving platform.
Continuity mistake: After breaking into the records room, Noah is looking at Samara's pictures or photo negatives, holding them up to the light, the shot of him show his fingers covering some of the first picture, but the next shot from his point of view the whole picture is visible and his fingers cannot be seen. (01:04:25)