Continuity mistake: In the scene where Warrick pulls the piece of clothing from the toilet, the amount of water and dirt in the bowl changes between each shot. (00:14:00)
Plot hole: A head without a body is found early in the show. Then, a body that has been decapitated, skinned, and severed of hands and feet is found. The CSI team assume the two are related until the coroner states that the body isn't even human. He also mentions that he has no idea what kind of animal it is and they'll need to consult an anthropologist. Everyone is shocked to learn the body is that of a gorilla. The body is humanoid (2 arms, 2 legs). It is larger than human size. The only thing it can possibly be is a gorilla. It must be a primate for having a humanoid shape and must be a gorilla because that is the only primate larger than man. There was no need to bring in an anthropologist (which should have been a zoologist if they truly had NO idea what kind of animal it was). It should have been painfully obvious to the CSI team, who are experts in all fields, that the body was a gorilla.
Answer: He doesn't have the authority to arrest him - when anyone is arrested in the show, a police officer does it. Also he tells Ty that he is going to be submitting his case findings to Ty's insurance company, who would no doubt contact the IRS, who then would have him arrested for fraud etc.