I think the previous appearance of a quote about this Sherlock Holmes quote bears out its falsity, except for Laplace's Demon-type intelligences.

The statement is a literally true statement as a matter of logical deduction. When using the words 'true' and 'false' then logic is what you are doing. Applying the word 'false' to 'true' statements is simply an error, as would be holding this particular quote to a different standard to any other logical claim. It has the same problems as logical reasoning generally does, those of assuming certainty of premises and relying on incomplete or incorrect simplified models. Focus on the dangerous not incorrect because accuracy just is not the flaw.

Instead of false consider (something like) "f@#%ing stupid". Or you are just wrong.