From what I have been told in the past, 12mph over the speed limit is considered Negligent driving, Which is probably where the large ticket came from. If he claims that he clocked you going that fast then he probably gave you a neg. Were there any other cars anywhere near you that he could have gotten you confused with? I don't see any excuse to cuff you and start yelling. I was caught doing 20 over last summer (i was 17). Trooper pulled me over, ran my plates and let me go. :p