I personally think that it should be a different system from this. Rather than just getting no rewards for any punishments of the last couple of months of the season, it should reward players who don't cause problems season-long with a point system. Different levels of punishment give different numbers of points. Points from the previous season steadily fall off over time spent without any reports at all. Anyone who has more than the disqualifying number of points at the end of the season is disqualified from the rewards. Certain things that sometimes can't be controlled - like AFK - generate temporary points, which fall off at the end of the season no matter what.
That's just my opinion as to how it should work, not how it actually works.