Continuity mistake: When Sara is waiting with Greg for the results for what was inside the tyre that exploded, she grabs the paper straight off the printer, reads it, looks at Greg and takes off immediately to inform Gil. When Grissom looks at the paper, you can see Greg's name is signed at the bottom as confirmation, but he never got anywhere near the paper.
Factual error: The CSI crew set up an experiment. They put some chloroform into the tire, set the bus on a dynamometer (or some other testing platform) and wait for the tire to fail. The tire fails in the experiment in the exact same amount of time as it did in real life. Problem: They have no idea how much chloroform was used and it would be impossible to match it by luck. More chloroform used would equal quicker failure. Then, there is the heat. The tire traveling over the hot asphalt road would build heat faster then on their testing platform. More heat would mean a quicker failure, too.
Factual error: Sara calculates the time needed to sabotage the tire at a minute to a minute and a half. That is, remove the valve core, allow the majority of the air to escape (cannot pour anything into the tire while the air is escaping) pour in enough chloroform to sabotage the tire, replace the valve core, and air the tire to pressure. Even with an industrial air compressor, it would take over 2 minutes to air that tire to full pressure.
Continuity mistake: The Camaro at the crash scene is a late second generation model (built from 1970 - 1981), however in the flashbacks to the crash it's a third generation car (82 - 92). The difference in body styles is quite pronounced.
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.