Shouldn't have honked. Did you really think it would have gone well? You could have just been thankful for not T-boning a cop, but you had to push it further. Granted, the cop seemed to be totally in the wrong, but you never gain anything from telling him about it. Maybe you can ask to look at the video evidence because supposedly if the lights are on, their camera is recording. That way, you can hear anything that the cops say in their car or to you, so if they were talking in the car about trying to find a way to screw you over, then you might have some good evidence, especially if it shows on video that your tag lights work.