Create Player Moderators already!
Seriously, almost every game out there has PMods. I think that every MMORPG has PMods, and quite a lot first person shooters have as well. Why can't MOBAs, and in particular, League, have PMods?
Seeing how the punishment system is flawed and can't detect a lot of things, like inting, Riot should entrust players to become PMods. Apart from having instant power of muting players who verbally abuse others, they could also have their report being more powerful.
For example, let's just say there is a 0/10 player in one team. If I report that player, probably nothing will happen, because there's not enough data that this player does this repeatedly, or they can't know if they did it intentionally or if it was just a bad game. Instead, if there manages to be a PMod in that game, they can identify such a case and report that player. In this case, PMod's report should provoke Riot's employees to watch that game and figure out for themselves.
Assuming that PMods are legit and care about the community, and any of their reports are 100% legitimate and have reasons, it could help vastly. Instead of having a programmed system, which is flawed, and just a small amount of people to monitor the vast playerbase of league, Riot could instead make 1% of the population to be PMods. I do believe that it would serve the system very well.
PMods can be selected through something like the Honor system.