There are laws about passing on the right in Ontario:

Section 150 of Ontario’s Highway Traffic Act states that using the right lane for passing a car in the left lane is legal as long as it can be done safely and one of the following conditions be met.

The law states the car you’re passing must be making or signalling a left turn; that the road must be wide enough for two lanes of traffic in both directions; or that the highway be designated for one-way traffic only.

theglobeandmail.com/…/article-is-it-legal-and-saf…

So it’s straight up legal on multilane highways. Which I didn’t know.