A Bullet Runs Through It (Part 2) - S6-E8
Revealing mistake: When the dead Cirque de Soleil investor guy (the one that bled out in Super Dave's body bags) is on the exam table, you can see him breathe twice, despite that his stomach and ribs are cut way open for Doc Robbins autopsy.
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.