Should I file a harrment suit?

You could pursue it, however, my personal opinion is that it won't be worth it. I'm sure there are other things that are much more important that you could do with your time. Plus, you didn't have to get worked up when he said he thought you were talking on you cell phone, you can easily get your service provider to send you doentation of your calls that day, thus proving you were not on your phone at the time you were pulled over. I personally would have just let the officer give you the ticket and then made him look like an idiot when you went to your court appearance. Much more satisfying to see his face when you prove that he's an idiot.