Plot hole: When Kim is brought back to the police station for the last time, the officer explains to her that they now know it was Gary Matheson who killed his wife, and that they are still looking for him. Why then, would Kim and her police escort not even consider the possibility that he might be hiding at his home when they arrive to get Kim's belongings? Even if the police searched the house once before, you would have to be insane to allow a teenage girl to enter the home of a known murderer on the loose. Beyond that, Kim herself never seemed to consider the threat.
Revealing mistake: When Michelle is in the van, waiting for the computer to finish analysing the conversation between Alex Hewitt and Sherry Palmer, the computer bleeps to says it has "heard" enough of the conversation to be able to recreate Hewitt's voice. How ever, it bleeps whilst Sherry is in the middle of talking. The computer should have made the noise about 15 seconds before.