In the scene, towards the end of the movie, when Kate suspects Adam of being the murderer, she says, "Stay away from me." Adam says, "Come on Kate," and Kate then smashes a wine bottle over his head. If you watch closely enough, you can tell that the bottle breaks mid-air before ever connecting with Adam's head. That brings up the question of what actually happened to that wine bottle, and if Adam was if fact struck by the bottle, wouldn't he be bleeding??