Over the years I've noticed a lot of small town law enforcement wear the "retreating shoulder flag" on their uniforms. I've wondered if it was supposed to be some symbolic thing, sorta like the military guards the frontier and the thin blue line is the vanguard of civilized society. But mostly I think it's because, just because it is.
Boy Scouts wear it backwards too, I never understood that (it was a Boy Scout who corrected Archie Bunker on flag etiquette, so they usually know what they're talking about) but their explanation is that when the flag is worn on the right shoulder then either is correct- the star field top left like a static display or the star field to the front like you're advancing.