Using probabilistic logic is perfectly reasonable as long as you track the stacking likelihood it’s wrong. However, making a probabilistic argument without tracking the internal probabilities is a Fallacy.
ie: Saying A which is true 90% of the time and B which is true 90% of the time so given A and B then C sounds reasonable until you continue with given C and D which is also X% true…. The individual probability that A, B, or D is wrong makes the chain of reasoning rapidly worthless.
Thus the error is using probabilistic statements without acknowledging they weaken an argument.
Are you saying that "You should know A is true 90% of the time." is a fallacy unless I add an explicit disclaimer about probabilistic weakening? Even if I'm not making any conclusions based on it, just suggesting people will want to use that information themselves?
If you're not saying that then I don't understand how anything you just said is relevant to the current situation. Telling people to look up a guy's writing history is probabilistic but it isn't turning that into an unjustified boolean statement.
That said while broken clock could happen to be correct, pointing out a clock is broken or someone is a nutter is still useful information.