Once your insurance looks into the police reports (they do every couple of years at renewal).
edit: I got clarification from my LEO friend, disregard much of this below, I was missing pieces of the puzzle.
It's my understanding that insurance companies look at two things – your driver abstract, and your autoplus report.
The Autoplus report won't show anything in the case of a non-charged accident with no claim since it only shows claim history and insurance coverage as I understand it.
Your drivers abstract shows convictions, suspensions, and criminal code charges. It does *not* show non-charged police issues, aka "police reports". Again, this is based on my experience with drivers abstracts - in my line of work I've seen lots of them and they don't contain every nitty gritty detail about police involvement, they show the nuts and bolts - tickets, suspensions, points, licence class. They don't show "Got pulled over because he had a headlight out, no ticket just a friendly reminder" type things.
Heres some one interesting reading on what your abstract shows.
https://www.insurancehotline.com/checking-your-driving-record-in-ontario/
Yes, insurers typically only run your abstract every few years (although they WILL run it immediately for new business obviously) but again, it doesn't show everything.
It's entirely possible I'm wrong (hey, I'm just throwing jello at the wall here), however I still don't see how they would become aware of an accident in which the officer used his discretion to lay no charge, and no criminal code charges were laid that would reflect on the abstract regardless.
The only exception to this could possibly be the "Restricted" abstract mentioned in the above link. It's unclear if insurers have access to this however, at which point without doubt such police incidents would be listed
Ill see see if I can get an answer purely for curiosities sake now.