Revealing mistake: In the scene where the CSI team first arrive at the crime scene and Grissom is taking photos, the first photo he takes, you can see that the victim's eyelids flutter a bit and his belly is seen contracting, a clear sign of breathing.
Revealing mistake: The dead baby is obviously a doll.
Getting Off - S4-E16
Revealing mistake: When Sarah and Catherine are looking over the body of the dead clown, in one scene his eye flutters and in the next he distinctly takes a breath.
Revealing mistake: You can see naked fitness guy breathe while he's lying on the morgue table.
Dead Ringer - S4-E20
Revealing mistake: At the beginning of the episode, when Grissom notices the body and pulls over, in the close up of him you can see that the steering wheel never moves: he just moves his hand to make it look like he's pulling over.
Revealing mistake: Dead antiepileptic guy is breathing while on the examining table.
Revealing mistake: The outline of dead Ice Guys underwear can be seen at the very bottom of the screen when Catherine and Nick take a DNA sample from his ear.
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.