Actually, it's pretty common knowledge here that there is a reciprocal agreement that tickets and points in either country are applied where you're at. We say the same things about Americans with MI and NY plates that blow down the 401 at 4kmh over the limit. The Provincial Police loves those guys.
If a cop on either side of the border throws a hefty ticket, it's got less to do with "teaching them a lesson" it has more to do with the fact that you're less likely to make a second (or third) trip to the court in the locale that the offense occured to defend yourself. And because the fine carries over to the offender's license then most people just pay the fine. Bonus for the cop; they get to write a ticket, get a big gold star on their forehead and not have to be a witness in court. Slam dunk.
I don't know how "common" that knowledge of that is. Maybe we'll find out if the old man knew.
I used to travel in Canada a lot when I lived in upstate NY and I always kept a sharp eye on my speed, especially when in a predominantly French-speaking area.