
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)
Answer: If you remember, Dorothy kind of stumbled into her friend from around a corner before they both fell down the stairs. Adam could have quite easily forced her into the costume and then pushed her, making her seem like she was trying to attack her friend.