Factual error: SPOILERS! While the ending of Al being arrested for murder at his own wedding is dramatic and cathartic, it wouldn't have happened that way. There's no way that the cops would have known to search the wooded area near the cabin; they would have needed to find physical evidence linking the cabin to Al; they would have needed to establish that Al had no alibi for the time in question; etc. None of that would have happened that quickly or that quietly.
Continuity mistake: The fragments from the truck's taillights that Cassie smashed with a tire iron were obviously "neatly rearranged" (and looked resized to be more uniform) before showing them after the man drove away. Cassie hit the outer sides of the rear taillights and fragments of various sizes scattered, so all would not settle close together along the bumper. One large fragment from the passenger side flew past Cassie behind the truck and landed about three or four feet away but was not there afterwards.
Deliberate mistake: A shot of the pile of ashes from the fire wherein Cassie's body was essentially cremated showed Nina's half of the broken heart necklace sticking out ABOVE the ashes, which would be impossible. Also, a metal charm on a chain that was around Cassie's neck would not survive the huge fire or be totally clean and unscathed.
