That is strong evidence that he isn't, but short of proof. A counterexample from California: https://en.wikipedia.org/wiki/Ron_Unz
Insofar as it was ire against your implication that "there is no proof against it" would somehow validate the insinuation, it wasn't.
And, sorry, even if you claim that that wasn't what you meant to do, the mere mention of it does imply that. We don't (AFAIK) have absolute proof that the Moon isn't (mainly) made of green cheese, either (those moon rocks the astronauts brought back could just be part of a thin rock crust over the cheese[1]), but what does it imply if I throw out the claim "We don't have proof that the Moon isn't made of green cheese!" in a general discussion about cosmology?
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[1]: Aha, so "Moon Pie" should be a cheese pie!
But it doesn't warrant an unprovoked single-party invasion. We're better than that these days.
> That is strong evidence that he isn't, but short of proof.
It's about the strongest evidence possible. Also, I'd think a person who's such a raw contradiction of "Jewish Nazi" would show signs of obvious psychological illness (either as a cause or a symptom, e.g. suicide to help the final solution along).
Add to that the fact that the claim he's a Nazi have all the hallmarks of a lie concocted to fabricate a moral reason for the invasion, by people with a history and strategy for creating such lies, and it's proved false practical sense. It's proven beyond a reasonable doubt that Zelensky is not Nazi, in fact it's even proven beyond most unreasonable doubts.
> A counterexample from California: https://en.wikipedia.org/wiki/Ron_Unz
I don't think so. Ctrl-F "nazi" -- zero hits.
It's not as strong as the synthesis of all the other evidence, particularly: his actions and statements throughout life, none of which point towards him being a Nazi. That is stronger evidence than his ethnic identity.
With respect to Ron Unz, you might want to read that wikipedia page more carefully than a quick C-f; that guy is a big fan of Hitler and hating jews. The same synthesis of actions and statements that vindicate Zelensky will plainly damn Unz.