Continuity mistake: The knot of Aidan's tie is done in at least three different ways during Katie's wake: When he puts the flower down before Katie's picture, when he walks down the upstairs hallway, and when Rachel speaks to him in Katie's room. (00:12:35)
Continuity mistake: When Aidan and Noah are talking in the car, outside of Katie's house, Aidan is coloring on a blue lap tray. When Rachael comes to get him out of the car a couple of minutes later the lap tray is now green. (00:51:25 - 00:53:10)
Continuity mistake: On the way to Shelter Mountain Inn Rachel is seen driving along a lake. The water is to her right, and the forest to her left. A helicopter shot confirms that, but when we see the car from the front the forest is to her right. (00:20:45)
Continuity mistake: When Rachel gets dressed for the wake the black brassiere under her white undershirt is sometimes visible, sometimes not. (00:11:55)
Chosen answer: Samara broke her finger nail clawing at the walls of the well... I guess that's why it's on the tape also.
Paul Plesser