My guess was it was a fake ID charge or something. Once while stopped at a stop light a cop pulled me over and gave me a ticket????
Seriously I was stopped, but he claimed I had been speeding some place back. I challenged it and they let me plea to a faulty muffle and a minimal charge. I laughed and took it. So the charge you plea to may have little to do with what you actually did. That means our guess that it was a fake ID situation can only be a guess.
My lawyer friend, while doing an internship, assured me that many people plea to lesser charges that include crimes they did not commit. Once in a blue moon this will come up again in court, and they are able to claim they were convicted of something they didn't do. Which is true.