I always believed that pacing was BS and I had called him on it, I guess not. Maybe he let me off cause I had a long night.
Pacing is definitely admissible. When I was younger I got a careless driving ticket (yes, not speeding but careless driving). The cop used his car's speedometer to measure my speed. When they use that as "proof" it is game over. You can't prove otherwise unless you can prove the car's speedo wasn't calibrated according to schedule.
The court places more weight on what the cop says over you so if it comes down to a he-said-she-said type situation, you WILL lose.
In my case, the cop only followed me for a "few seconds" according to his notes. He said I was doing 140kph on the 401. Of course it was BS because he got me driving home from work during RUSH HOUR. I got service records for his car and they were up to date so I couldn't use that. Instead I focused on his lying to "discredit the witness".
In order to get me for careless driving and not just speeding he had to prove that I was driving "without care for others" and being in a dangerous situation, etc. etc. In his notes, he tried to show this through various "dangerous lane changes", etc. etc.
I thought I was prepared. I looked up the weather on the day of the offence and got aerial photos of the section of highway where I got pulled over, etc. During the trial the cop said it was raining and slippery. It was not, my weather report from environment canada showed 28C sunny. Cop disagreed with it. I asked how can you remember since it was not in his notes (the court date was 1.5 years later)? Cop just said he remembers. Court chose to believe the cop despite my evidence.
Second, according to the cops notes I changed 6 lanes. I showed in the aerial photo that section of the highway which cop agreed was the subject area. I said, count the number of lanes. If I had changed 6 lanes I would be in the ditch. If I had done that, it would definitely be in his notes. It was not. The cop's response was that there was construction on that day which is why the lane configuration is different. Really? Since when does construction ADD lanes to a highway? No response. Court chose to believe the cop.
I caught the cop in MANY lies (those 2 being the strongest in my favour) but it didn't matter. The court believed the cop. That was my first ticket and has made me HATE cops/court since. Before we went up, he came to me and told me he has never lost and I should settle. Being young, I was thinking today's the day he loses because I have evidence he is a liar. I just told him I want a chance to defend myself. To add insult to injury, after we were done and outside the courtroom, he came over to gloat.
Years later, I came to know an OPP officer and asked him if he knows this person. The response? Oh ya, I know that guy! He's on some serious roid rage. Awesome.