Continuity mistake: Samara, as seen in the psychiatric sessions on the videotape, has a prominent gap in her front teeth - yet when she decomposes in Rachel's arms down in the well, the skull that is left has perfect teeth with no visible gap.
Continuity mistake: After Noah sees the video at Rachel's place he joins her on the balcony. His hair is hanging over his face but when they go back in it's combed back. (00:29:20)
Continuity mistake: After Noah is killed by Samara, Rachel comes in. She steps up to the chair Noah sits in, looking away from her. She rotates the chair counterclockwise to look at him. We don't see his face yet. We do see it near the end when Rachel has a flashback. For a split second, Noah's face is revealed in the chair now rotating clockwise. It should have been turning the other way around. (01:43:40 - 01:46:05)
Continuity mistake: In the extra/cut scenes included on the DVD, there is one where Rachel is in Katie's room snooping around. She goes over to the cabinet that has the TV on it and opens the top drawer, rummaging through it. After looking, she closes the BOTTOM drawer even though she was looking through the top one in the previous shot.
Continuity mistake: When the horse breaks loose on the ferry it gallops down a narrow corridor towards Rachel to finally jump over the railing. When you look closely, especially at the car parked at the end, you see that the corridor changes in alternating shots. (00:55:35)
Continuity mistake: When Noah drops Rachel off at the ferry and hands over Aidan's drawing it is pouring. However, only in close-ups of Rachel we see rain coming down in front of her face, but not when the camera shows Noah. (00:52:45)
Suggested correction: You actually can see the rain falling when the camera is on Noah. It just isn't as noticeable because of the lighting. It's similar to if you look outside during a rainstorm at night and you can't see the rainfall that well unless you are looking at a street light or porch light.
Continuity mistake: When Rachel lifts Samara out of the water in the well, Samara's hair changes position from shot to shot. First there is no hair on her face at all, then there's some draped across her neck and down the side of her face (which Rachel moves), and finally when Samara "decomposes", the hair across her neck is gone as well. (01:33:00)
Continuity mistake: When Rachel is approaching the top of the ladder upon entering Samara's room at the stable, the camera is following her from behind and it shows her reach the top and wait there for a few seconds, yet when the camera shows a front on shot, she hasn't reached the top yet.
Continuity mistake: Rachel goes to the lodge reception and the clerk points out the tape collection to her. She turns and is drawn to The Tape in the centre of the shelf. It is lying sloping up to the left, label spine outwards, spools on the left. When Rachel picks it up to drop it into her bag, it is spools to the right, label spine inwards.
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)
Continuity mistake: Naomi Watts' dark roots change length throughout the movie.
Continuity mistake: When the woman is watching the film and trying to see the lighttower, she has blood in her nostrill even though she has not yet started to bleed.
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)
Continuity mistake: At Katie's wake Aidan approaches her picture with a condolence book in front. There's a pen lying on the book with its tip pointing towards the picture. When he puts down his flower the tip is pointing at him. (00:12:45)
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)
Continuity mistake: When Rachel first meets Richard Morgan during their conversation, Richard's jumper and collar are green in some shots, but blue in others; it's very noticeable as he opens the cupboard and cleans his shoes. (00:59:30 - 01:02:30)
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)
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)
Continuity mistake: In the scene where Rachel approaches the horse and the horse starts going crazy, you can see the ring at the end of the rope securing the horse break away from the trailor. In the next sequence when the horse is running around on the barge, the rope is broken with no ring.
Continuity mistake: When Noah is at the supermarket buying cigarettes, he pulls out of his pocket a bunch of junk such as coins, trash, and an old pack of cigarettes and dumps it on the counter. In the next shot of the counter, all the junk is gone except for a coin, and the old pack of cigarettes.
