One man in my home ward knows a cop in the Provo area who they call "Red Bull DUI" because he cited multiple people with DUI's when they had open Red Bull cans in the car. All those charges were dropped within ten seconds of being read in court, obviously, but there was no retribution for the cop as far as I know. The general practice seems to be to let the cops cite a lot and let the courts decide whether you're guilty or not; if the citizen is obviously innocent, no harm done (theoretically), so the cops wouldn't get in trouble.

Note that this isn't a judgement on all cops--there are many, many, many good cops who are legitimately just trying to keep people safe and who only issue reasonable citations.