I'd be a "dick" to if I had to deal with low life scum my whole work day.
But seriously, show teh cop some respect, answer his questions, address him formally, and your all good. The more additude you give a cop the more your ass will be in trouble.
I always love watching those shows where the cops tell the guy to get down and the guy is like "wait wait let me tell you what happened, im innocent and didnt do anything wrong!!" they tell him a few more times and then have to force his ass down

If a cop tells you to do something, do it no questions asked. You'll have plenty of time later to explain yourself.