First, how do you know that he heard EXACTLY what you said? Suppose all he heard was "mumble mumble dumbass?" Can you see how you might have played your part in this little endeavor?
Second, if your seven year-old daughter was in the car with you, why would you even use that terminology. How are you going to feel when you hear her calling one of her friends a dumbass?
Here's some advice from a guy with a lot of years under his belt: It NEVER pays to be a wise guy when you're dealing with the police. Challenge their authority and you are going to lose. It may simply be lost time, such as this incident, but you will NEVER come out on top acting like an ass. You told him to do what he had to do and I'm sure it was in a tone of voice that made him do what he COULD do, to teach you a lesson.
Police deal with scum all day long. They neither need nor appreciate regular, normal citizens wising off to them.
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