What can you in chat?

I have a question regarding in game chat. Is it allowed to have an argument?The best i can play this,is by giving an example of one of my games. I had an yasuo who fed, like really fed the enemy.I didn;t told him anything, the game was lost anyway.At one point, the yasuo pointed out a mistake that i made and blamed me bcs i didn;t gank his lane at level 3(he was vs LB).Now,this really triggered me.This is how i see it.This guy lost the game and has the balls to say something about a mistake i've made after the game was over(yasuo had at that point 10 deaths in 15 min).Withouht being insulting or saying any bad words,i told him, that he has no right no judge by play after he died so much.I even said that,it was not possible to gank his lane,since he was death everytime he came to lane. I was not using bad words or anything like that.Idc how you play.But dude,besides the fact you lost the game,atleast have the decency to shut up and aknowledge your mistakes.

And in any given scenario,where someone makes huge mistakes and then not only blames you, but points out your own mistakes(if you have any)

Just whant to know if this kind of behaviour is bannable.I never say "report x" or stuff like that.I sometimes get triggred by this kind of thigs:)..but i never use insult or flame on them.Sometimes i may make some sarcastic comments. but that's it:) what do you guys think about this?