Someone said its only normal game with 2/22 score?

Were they actually inting (i.e. dying as much as possible because they wanted to help the enemy team)? The last time I played Vayne in PvP, I tried my best in laning, splitpushing, staying at the backline in teamfights, etc., but I went 0/18 in 50 minutes.

It looks like you're ignoring their assist score.

Rito: "Just a bad game."

TBH if he just ran down lane, he might be punished for it :)

Given how easily we can find the player in question through OP's match history, I wonder if this counts as naming and shaming?

And OP, X deaths within Y minutes alone do not make it intentional feeding. Based on the fact that you made this thread, if I had to guess anyone did something that would deserve punishment in that game, it would likely be you.

Laughs in inting Sion "strat"

I think you're skipping over the intentional part of intentional feeding. Intentional feeding means someone is actively trying to give the enemy team kills. 2/22 really isn't a score you'd expect from someone who's inting, as it's quite easy to die in league. Either way without a chatlog it's impossible to be sure about wheter or not someone is inting.

Intentional feeding is certainly punishable.

It doesn't matter if the person went 0/50/0 or 0/1/0.

Judging by the ELO and their death locations, they're just bad. I don't mean to attack you personally at all, since we've all been there, but in my humble opinion, nobody is doing well in that match. In a whopping 46 minutes, the highest CS score in the game was your Runaan's equipped Teemo with a meager 214 farm. I can't tell who on your team was nominally the support (maybe the Taliyah in question?), because everybody's CS is so low, and summoner spells are all over the place. The enemy team had a consistently massive gold advantage over you, yet couldn't figure out how to end a game before minute 46. This was a fiesta.

I can't swear that your teammate wasn't intentionally feeding, but I doubt it. Rather than focus on the weakest link on your team, you'll do well to focus on becoming the strongest link yourself. There was plenty of opportunity for you to hard-carry this game where you wouldn't have even noticed how poorly Taliyah was doing until the very end.