His situation happens all the time. You are cruising at what ever you have your cruise control set at and someone going slower than you is in the passing lane. You give the person some time to move over and they don't. Finally you go to pass in the right lane and the person you are passing decides to speed up so you can't. OP stats the vehicle in the left lane was traveling between 58-88, so that tells you the car they were passing was not speeding until they were being passed.

This is a very frustrating situation and I can see why you sped up to get away from that driver. That being said, regardless of why you are going 100 in a 70, if you get pulled over the ticket is absolutely warranted. I would agree to with just paying it at the plea deal rate and moving on. Bright side is at least you don't have to pay for parking.