Cops have A LOT of leeway with what the do and don't enforce. In one of my more embarrassing moments when I was younger, I was pulled over after having a few too many. In hindsight, I should not have been anywhere near a car, but I was 22 and stupid and nothing was going to keep me from going to this girl's house. I was very respectful to the officer, cooperated fully, didn't argue, and did my best to make the whole process as quick and painless for him as possible. He ran my plate, saw I hadn't had even so much as a parking ticket, and just gave me a ride home. On the way home, he told me he was giving me a break because from what he could tell, I was a good guy. Told me he appreciated me not hassling him about the sobriety tests, even though he knew we already both knew what the situation was. Since then, I haven't gone anywhere near a car if I've had even a single beer. I got away with one, and I doubt it ever happens again. But really, it just shows that an officer pretty much decides what he is going to do independently. I'm sure he has ongoing instructions from his superiors, but at the end of the day, it's their call...