Continuity mistake: In the scene right after Shelly's funeral when Kate and 'Adam' are talking by his car, he goes to kiss her when they are done. He tries to kiss her on the lips, but she moves to the side. At first he is kissing her on the left cheek and when the camera changes positions, he is kissing her on her right cheek. (00:17:50)
Continuity mistake: When Dorothy is letting Campbell live in her home, he picks up his bag and puts it on his shoulder. When he leans in to kiss her, there is no strap on his shoulder, then it's back again in the next shot.
Continuity mistake: Shelly stabs the killer in the leg with the scalpel. But when we see the killer following her, he seems unhurt and there is no blood or anything.
Continuity mistake: In the scene when Kate is in the shower, in the opening shot, in her lounge the camera pans past a bookcase and into the bathroom. Kate then hears a noise, gets out the shower, and finds the water is cut off. When she uses the phone, halfway through her call, her iron overheats. The iron and ironing board are right beside the bookcase that the camera panned past in the opening shot. Trouble is, the iron and ironing board weren't by the bookcase in the opening shot. (00:21:50 - 00:23:30)
Continuity mistake: When Paige is in the hot tube, minutes before her death, you can see the killer looking at her. There is a noise, and she looks back for a few short seconds but there has already been a rose placed there for her BEFORE she turns around to see what the noise is, she just doesn't notice it until she turns back around.
Continuity mistake: When Paige is thrown in the hot tub by the Cherub, he pulls the cover over. Where did it come from? You don't see it before she is killed.
Continuity mistake: At the end, when the killer leaves Denise Richards a rose, you can see how badly the scene has been edited. If you watch closely you'll see that the rose appears from nothing - one moment there is nothing and the very next moment it is there, and it certainly doesn't look like someone's putting it, as it should be.
Continuity mistake: When Paige is upstairs with that guy, she tells him to take off his pants and shirt and then she kisses him and places her hands on his chest, but when the camera angle changes just before she throws him on the bed, her hands are on his arms.
Continuity mistake: When Ruthie hits the killer with the pool stick, he has a long coat which goes down near his feet, but when he throws her through the shower and is trying to push her head down on the glass, he has a short coat which only goes down to his knees.