Sure they will be able to see that here or there in that particular case the circumstances were fishy, maybe they even put the old system to the test and found it lacking, no doubt there. The error is in your next point:
As you stated yourself it would be a task beyond any mortal to go and look over each individual ban, the exact circumstances that led to the ban and review whether FF worked properly that day, or whether some GM had cat-piss in their coffee this morning and was banning for the most harmless things, or if these persons got banned for things unrelated to cheating even.
I am not quite sure what the latest count on ffbans.org for cheaters only was, but it would have been somewhere in the six-digit range.