Most people just accept that what a police officer says is 100% objective in the eyes of the law. While it’s certainly never a good idea to get into a confrontation with an officer by arguing with them, you’ll have your day in court.
The thing about the law is that often it’s very subjective. For example, you could get a ticket in Thornhill because you made an unsafe left-hand turn. Says who, though? The officer who wrote you the ticket. It’s worth showing up to court and disputing that assertion. Tell the judge why it was safe. Usually, the traffic cop won’t even show up to retaliate meaning you have a pretty easy case ahead of you.