I just finished a great close game with my premade team. At one point, it could've gone either way, but we had a good teamfight at the end and won out. Imagine my surprise at the end when instead of saying "GG WP" like the rest of us, the enemy team is saying they're reporting me.
Earlier in the game, Fiddle had been camping my lane and I said to him "Fiddle, stahp D:", obviously in a joking manner. By 20 minutes in, I was 8-0 and the enemy Jayce decided he was going to get really mad about this. He starts saying "Reporting Kat for ****-talking" and saying that I was "cocky" and had just "gotten lucky" after I got a triple kill thanks to a good play by my support. I did absolutely nothing that was reportable except try and joke with them, but I guess you can't do that anymore.
But this Jayce and his friends were so mad they lost that they reported me. And they proceeded to say the most vile trash in end-game chat, saying I was awful even though I finished 16/4 with 350 CS.
TL;DR is I've been banned before, and really don't want to get banned again. I've completely changed my attitude in game and am winning much more often because of it. I don't want to risk getting banned again because people are sore losers, but it seems like it can't be helped. It's BS that false reporting exists and people who do it are pretty pathetic in my book.
I wish there was a better system in place to catch people who report because they lost and are mad about it. I really don't have any suggestions though. Maybe someone else does. I guess it would give me peace of mind knowing it's being worked on. Thank you.
There is not much you can do to 'avoid' false reporting; however, it really is not a problem anymore in the current iteration of the Tribunal. Every single report is assessed by the system, and false reports are identified very early and have little impact.
Although there are false punishes, the false punishes typically are not because of false reporting.