2/3 if this is like riots surrender votes then i guess nothing really.
As stated above, the system doesn't work like that. If you've hit the threshold of getting put into the tribunal, and some of your games are toxic, then people are liable to hit punish. You're getting punished for the case as a whole, not the individual games. It isn't so much a question of "Was this person toxic in all of these games?" as it is "From this random sample, is this a toxic enough player that they need a nudge?"
Also, before you play the "Everyone gets reported constantly so everyone gets in the tribunal" i'll head you off and say i've won 1000+ games. I'm pretty sure I've also played 2000+ games, given average distribution of wins/losses. I don't really consider myself a pillar of excellence. I know where my faults lie, and where I need to improve to be a more positive influence, if i so choose to be. I've also never even been warned by the tribunal.
In fact, given that the language used by riot when they post seems to imply that getting tribunaled is based on your number of reports, compared to your number of games, as compared to other players, everyone getting reported in 20% of their games wouldn't mean that everyone goes to the tribunal. It would just mean that only people getting reported in 40% of their games goes to the tribunal. Personally i feel like the average player gets reported in something like 2-5% of their games, and the average tribunaled player gets reported in something more like 10-20%, but those are just guesses on my part. Would be interesting to get numbers on that though, perhaps in the next infographic.