Recently had a game like this.
In champ select, I marked to play Ahri top. The midlaner saw that, said: 'Your Ahri will lose the game' and banned Ahri from me. Made me quite annoyed...I really wanted to play her. I picked Morgana instead. And our jungler picked Shaco. That guy said 'Don't pick Shaco, we need tank'
The midlaner picked Fiddel and said : 'I will troll' 'Morgana and Schaco will ruin the game.'
Game starts. The midlaner Fiddle types in chat again 'This game is lost thanx to Morg and Shaco' I decided to mute him, so I don't know if he wrote more on. I was winning lane. That Shaco did great as well. We won the game.
But I still reported that Fiddel for his behavior from champ select. I wrote the details in the note. But I don't know if it will be valid. (Assuming the Fiddle didn't have anything to complain at since we were winning so hard.)