Yes, I have occasionally been wrong, as have others. It happens. The last time I was "wrong" the person was actually pretending to be haxing, and at least two other people saw it and commented that it was hax, and another PM'ed me about it as well. The reason I'm usually in spec in the first place checking someone out is because a couple of regs playing at the time have said that they are sus.
Generally, if there are people on server I can ask about it (Blusky, Joker, etc) they'll either say "That's fred, he's fine", or "Seems sus to me too", or "Yeah, they just got a new mouse" or whatever. And then I demo, and either review the demo and then come back and ban, or ban then review (quite often, they aren't there when you get back if you do it the other way around). I'm not an expert on hax (be quiet Pen) so I do submit to the rest of OZ when it's an issue. If it's a case of an oldskool botter, snapping continuously across the map and then behind 160 degree turn to HS, no, I don't demo, or submit it.
In terms of the banning, yes, there are things that we can do - but given that we're pretty much all adults here, there's plenty you can do too. Like, I don't know, maybe sticking with an alias for more than a day? If you are you, and everyone on the server knows that you are you, and we know that you are you, you won't get banned accidentally.
That also does wonders for the ET community, and you aren't now playing with a bunch of random names, they are people you know, and love, hate, love to hate, or hate to love.