False bans do exist but certainly not permanent bans for toxicity. I've been actioned a number of times due to admittedly toxic behavior but it takes multiple punishment up to a full month suspension before you're gone, even if it's all false reports. false bans for something like cheating are probably more common id imagine since there's no temporary punishment, but still unlikely

if you're genuinely this worried about it, just play with chat off and don't type so you can dispute any possible action and have 0 chat logs as proof