Suggestion for tribunal system

Why is it that people cant be reported or banned for after game chat or champ select? Most toxic people i see are even more toxic after a game and say things that are far more likely to get them banned in the post game chat. It seems odd that this chat would not be considered when going to the tribunal since it is a far more effective place to catch a raging person. Just a thought for you to consider about the tribunal system :) attached is a chase and point.

This Cho was toxic the entire game but really went over the edge in post game chat. http://imgur.com/a/kxvLn

This guy ended up picking soraka top with cleanse and clarity. ended up forcing someone to dodge and lose his promo. http://imgur.com/a/Kth37