Continuity mistake: The short-haired brunette wannabe Lab Tech has a disappearing and reappearing necklace during her conversation in the lab with Warrick.
Revealing mistake: As the phone number 702-555-0192 is supposedly dialed, you can hear in the sound overlay that the last two digits dialed on the touchtone keypad were the same two digits. Then it shows a close-up of the cell phone dialing the above number.
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.