This is not at all unusual. Poincare discovered special relativity before Einstein, Hilbert found the correct equations for General relativity one week before

This is not at all unusual. Poincare discovered special relativity before Einstein, Hilbert found the correct equations for General relativity one week before Einstein, Hamilton almost discovered quantum mechanics decades before everyone else. Newton found solutions to major mathematical problems and never published them. Gauss discovered hyperbolic geometry before Bolyai and Lobachevski and never bothered publishing his results. I can go on and on in the fields of physics and mathematics which I know best. Certainly, the same thing is true in chemistry, biology, etc. I wouldn't doubt someone got there before even Feynman did. Still in every case, the recognized discoverer not only made their discoveries independently but also managed to convince their communities of their merit, something which is FAR harder to do. This smells like classic Feynman. He did more things than people realize even coming up with his own ideas about the Riemann hypothesis even though he wasn't a mathematician at all. In a certain sense Feynman didn't discover a single physical law. (arguable) . This little anecdote if true would be Feynman's "single" discovery of an actual new physic law (which happens to not have experimental verification). Feynman was brilliant. If you have a physics PhD you can still benefit enormously by reading Feynman's lectures on physics. His work on statistical mechanics is essential reading too especially if you already know everything.