Re: Vague Disclosure (attached) 60 in a posted 50 zone, reduced from 80
There's nothing preventing you from challenging the officer's testimony and going to trial. Its always beneficial for people like you to take matters to court when the odds are significantly against them. That's how the law gets better clarified. Since its your money, time and driving record on the line and only a few extra hundred dollars of YOUR money, don't let anyone dissuade you if you want your day in court.
Just know that the officer will have very little difficulty establishing time/distance since she can easily say she saw your vehicle approach from behind, pass her car and still be above the speed limit as you passed her. Assuming she says she saw your vehicle from 4 car lengths back and got behind you when your car was 4 car lengths ahead, that's a total of 9 car lengths (counting the length of her car that you passed). The average car length is about 15 feet; so that yields 135 feet which equals about 41 meters. Keep in mind that the officer's vehicle is moving at 80km/h which is 22.2 meters per second. Make sure you understand the concept of relative velocity.
Pacing can be done by several methods---yet, you seem to be fixated on the more common version of the officer following the vehicle for some period at a constant distance as your basis for dispute. That's not an essential element to pacing.
Remember, in your case, the court will have to grapple with how it was possible for your vehicle which was going 50km/h to be able to pass the officer's vehicle that was going 80km. 