Competitive Match Cancelation Rules Inconsistent

What exactly are the rules for when a player leaves a game of competitive?

There have been several matches this season where a player from either team has left very early in the match (within the first min and a half) and the match was not been canceled.

It feels like the rules for if and when a competitive match is cancelled without penalty due to a leaver is extremely inconsistent.

it only cancels if one player was afk

they recently changed it so it’s possible to have a leaver early and not have the match cancelled - this happens if said leaver did any dmg/healing during the beginning of the match
so if you or the enemy team had a leaver after the first fight the match isnt gonna cancel only a true afk cancels it now :confused: