Continuity mistake: Season 9, episode 3 "Art Imitates Life": When J. Skaggs is being interrogated by Brass he has his hands on his lap. In the next shot they are both on the table.
Continuity mistake: When Sam the police dog picks up a bottle of water with his mouth from a cooler, he picks it up from the top. In the next frame, he gives it to his trainer horizontally.
Continuity mistake: When Sara has finished processing Melanie Grace at the slot machine, Melanie gets down from her chair and a uniformed officer can be seen helping her down. However in the next shot the officer has disappeared completely.
Continuity mistake: Season 11 - Episode 20 "Father of the Bride." As the doctor's wife is sitting talking with Nick about Vegas being the fugitive capitol of the world, watch her hands. At first they are spread far apart on the table. The shot changes and they are suddenly crossed in front of her.
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.