Punishment System

Well resently a friend of mine got trolled and snapped during a couple of games...to be specific he got hard trolled...he is under quite pressure this days and plays just to have fun so he was pretty easily triggered by all this tha happened and flammed this guys and got chat ban...i know as he that he deserves the punishment he got but is it fair to be trolled and not react...i mean wouldnt it be more productive to punish the action and not the reaction ?? can anybody just troll and get out with it but when the one who gets trolled speaks about it get punished ?? is this even fair...