Since there are several threads floating around that are lying to uninformed players that Nightblue3 got a player "falsely" suspended, it seems there's a need to remind people about the actual rules of conduct for this game. The one most important in regards to this kind of ban would be:
#Rule 1: Support Your Team
Particularly paragraph 2, which states:
>Being a good team player **begins at champion select.** Be open minded when considering the needs of your team. If you're the last one to pick, try to fill a niche in your team that hasn't already been filled. If everyone's picked and something stands out as a **deficiency in your team composition**, try asking for another player to fill the gap, or change roles to embrace that responsibility yourself.
What many people fail to understand is that this means your "off-meta" picks have to actually _fill_ a deficit for your team. Not **_create one._** Which is what a pick like Teemo "support" is doing. Whether or not you agree with that interpretation, that is the interpretation Riot has always used when dealing out punishments for this sort of thing.
As for _why_, it's because it forces your team-- whether or not you attempt to communicate your weak legitimacy for the "strategy" in the inadequate time provided by the picking phase-- to pick and play entirely around you. Which is not what Riot supports, this being a team game. If you want to play like you're the only person who matters, then stop playing team games.
In addition, Positivity Bias plays a hefty role in people who do this sort of thing consistently. You can even see in the video where the guy makes the outrageous claim that he thinks he wins with it 65% of the time, when in actuality he _loses_ with it almost exactly that often, at a 63% loss rate.
He also goes on to say, "if people want to dodge, that's fine." Which is the most obvious violation of the Summoner's Code in the video. Despite his attempts to fool himself when his performance is literally opposite what he thinks, he knows well enough that it doesn't work to know people are going to be dodging. And this isn't a case of some Iron 4 newbies not knowing Teemo bot is super op thanks to him getting massive buffs or anything. This is Master, where the players have the knowledge to be open to new strategies. And to know when one simply wouldn't work and forces the team to play entirely into the troll's hand.
Lastly, do remember that punishments like this aren't the result of a single report. Spend any amount of time on the Player Behavior board and you'll see plenty of examples where the game provided by the feedback wasn't really the worst example of the player's behavior. It takes several reports over several games to get a suspension like that. And considering the guy did it over 20 games with an over 60% loss rate _in Master tier_, it's hard to imagine he wasn't reported by at least the ADC in every one of those games.
Video evidence found here: https://youtu.be/aIy8JUxaW7I