Plot hole: In the scene where she goes to her house after escaping there is no police tape on the front door even though it is a crime scene. Earlier the police searched and taped her office - it only makes sense that they would do the same to her house.
Plot hole: When the innkeeper is asked by the rich ex-actress to give her the key to a nice room, he gives her a key telling her that eight is cozy and the key has an 8 on it as well. But a few minutes later, when this woman is about to be murdered, she leaves her room (holding her mobile phone) and the door has a 9 on it. How can a key to the room 8 open the door of the room 9? [Still a mistake, but there's an explanation. In the DVD extras you can see a deleted scene in which she changes rooms because she wasn't happy with 8.]
Plot hole: How did a woman who had just escaped from a mental institution get out of the country so fast? Even if she had a passport already, she wouldn't have it - the hospital or her family would. How could she get it back from them without SOMEONE turning her back in to the institution? It takes a lot to get involuntarily committed in the US, and I doubt she could get un-committed that fast, even with the guy she tried to kill vouching for her.
Plot hole: Just before Cowboy finally opens the bowling bag, the zipper is halfway up the right side. John was warned not to open the bag and was terrified by the potential consequences; he didn't open the bag at any point and certainly wouldn't have allowed it to remain partially open. (01:13:30)