How many games can you intentionally ruin before being banned?

Serious question. I saw that one Nunu guy with 60 games trolled in a row and no ban. Only reason he got banned was because somebody @RiotSupport and then even with 47 losses and building zeal items and going 0/10 in nearly 47 games they still tried to give him the benefit of the doubt. What's the line on the amount of games you're allowed to intentionally ruin without being banned? [Picture Removed by Moderation]
Reportar como:
Ofensivo Spam Mau comportamento Fórum incorreto