Continuity mistake: Cynthia walks alone to Joyce's house and also leaves by herself to clean the van. She speeds away from the house in order to clean the van in secret, but she somehow has her toddler son with her while she is cleaning the van. (00:46:45 - 00:52:16)
Revealing mistake: When Joyce and Cynthia are standing at the rear of the van, a carload of young men pulls up behind them. The men appear to take several steps before reaching them, so the car is not parked very close behind the van. When one of the men gets back into the front passenger seat, his car door is so close it looks more like it is the passenger door on the van, not the car. (00:34:14 - 00:34:35)
Character mistake: Cynthia Kellogg comes forward to voluntarily give information about the James Urbanski case. Detective Nealy tells Kellogg, "As a matter of procedure, I have to inform you of your rights." Kellogg says she didn't do anything so doesn't need a lawyer. Nealy replies, "This is your right" and proceeds to inform her of her Miranda Rights. Miranda warnings are applicable to suspects/defendants who are in police custody (under arrest) and about to be interrogated, not voluntary witnesses. (00:03:02 - 00:03:57)