Audio problem: When Gil is talking to the drug dealer in the desert, he refers to him as a 'dumb punk'. But this has been dubbed over as what he actually called the dealer was a 'dumb prick' which you can tell by Gil's lip movements. (00:23:50)
Audio problem: In one scene, when Warrick is in the prints lab, Nick claps his hands twice, but the sound track has him clapping three times.
Audio problem: When Nick and Warrick find the dead man's flying equipment, Nick says "Bingo" but his lips don't move.
Audio problem: When the Ranger is talking about shooting a coyote he says, "I took care of him." The shot is from behind and slightly to the right of the Ranger. When he says this line, his mouth is not moving.
Dead Ringer - S4-E20
Audio problem: When Sarah is interrogating the police woman, there are some shots from the left side of the woman when she is speaking and her mouth/jaw movement do not match the words that she is saying.
Audio problem: Warrick is examining the garage for evidence and sees a stack of crates of soda, he sees one has a bullet hole in it. He picks it up and shakes it, it rattles, demonstrating the bullet is still in the can. He pops the ring to open it and it hisses, despite the fact that the bullet hole in the side would have let the pressure out. They clearly used an unopened can to film the scene.
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.