Ontario Highway Traffic Act

Today I was apparently clocked going 99km/h in a 70 zone. The officer reduced my ticket to 15km/h over. I have a few questions;

1) While the officer stated to me that I was going 29km/h over, is it possible that this number is even higher?

2) If I select a trial option and decide to plead guilty rather than proceeding with the trial, will the ...