Leonardo da Vinci was human, he had flaws, he wasn't always right, and I think these are important things to point out in order to make the real achievements stand out.
Leonardo's flying machines were crap, which is to be expected when basic understanding of aerodynamics came hundreds of years after. Helicopters in particular are deceptively complex. And it would be a shame to put them on the same level as mechanisms he designed that actually worked.
I think it sets unreasonable expectations if you don't recognize the flaws of great men. And especially in science, being wrong happen, and it is not even a flaw.