Any time it's worn on someone's left side, the stars line up with the traditional image of the flag. Additionally, when it's on the front or back of something, there's no edge of the flag that is advancing.

So it's really only when a flag is in the right side of someone/something, and done properly, that you'll see it with the stars on the right. Meaning, most of the time it's the default stars on the left.

Any time I've seen real cops or EMS or anything with a flag on the right of their clothes or car, it's stars on the right. It's usually wrong on TV though.