I'd like to extend above answer a little. The systems in games like Smite and Lol actually got so good that amount of false negatives are so low that they are almost non-existent and can be handled throughly on case-by-case basis. I play Smite a lot in my free time, and I see how the system works from outside, I cannot count how many times I was thretened to be reported, and even if half of these threats were followed through I probably earened over 100 "Intentional feeding" reports by now, and I'm still playing without even one temporary ban. At the same time I've seen number of players disapear from leaderboard after I've reported them for harrasment (there was actuall harrasment, mother calling, death threats even), it didn't happen after my report, but few days later after few more matches all of haters sooner or later got permaban.
So the reputation systems came a long long way from where they used to be, false positives are no longer big problem, the biggest issue is now reaction time (time between player starting spewin vitriol to the moment he's prevented from playing), ideally it should not be few days (as it's now in most cases), someone having bad day shouldn't mean a bad day to all person he's teamed up with
One of the solutions might be "incremental" baning, by disabling some of the futures - which some games already do (and Microsoft is doing in this case). One of better examples is voice chat muting, I cannot recall which game id doing it. They way it works is the more people mute asshole, the more likelly he is to start muted in first place, his teammates might decide to unmute him, but there's no longer risk of "Beter not fuck up morons i need this win" welcoming you to the match.
I'm looking forward to further advancements in these systems, as playing team games on internet is still quite annoying these days, especially since you often get matched with people who don't speak english and/or you cannot just smack for beeing an idiot like you'd if you played football together.