Failing To Move Over

Just curious... Driving home tonight, I saw the flashing lights of a police car. I saw the officer get into his car and the vehicle that had been pulled over, drive away. With other vehicles around I choose to stay in the inside lane, as my exit was approaching. I took my foot off the gas and proceeded. The accelerated to the speed limit once I had passed the police car. The officer then pulled in behind me with lights flashing. I pulled over. The officer gave me a ticket for failure to move, when possible into another lane when passing an emergency vehicle.

It seemed to me, that the lights were not flashing on the police car as the officer wrote my ticket. Cars were flying by us in the inside lane. Seems counterproductive to the law I seemed to fail. When I said to the officer that I had slowed down, he said he clocked me at 88 in a 90 zone. Yes, as I accelerated AFTER I passed him....?? Do I have a leg to stand on or do I just pay the fine?