For me the issue is not "is Elon Musk an awful man". Yes I think he is, generally, an awful man.
Was Father Ted an awful man? Well, not as awful as Elon Musk but as others have said he was portrayed throughout as somewhat feckless, a moral coward and so on. And the setup for the Hitler scene included him doing some essentially racist caricaturing, so that his nature had already been called into doubt.
As I have always understood it, in that scene, we are supposed to see that there has been some bad behaviour from Father Ted, but when he appears at the window saluting with a Hitler moustache, we are not supposed to understand that Father Ted has set up some kind of "plausible deniability" scenario where he can openly and intentionally do a Hitler impersonation. We are not supposed to assume that he pre-arranged for the black square to be on the window. We are supposed to some unfortunate things conspiring to make him look loads worse than he really is. The setup is of course important - we know he's not an entirely innocent party.
(By the way very similar scenarios are the core of pretty much every Curb Your Enthusiasm episode)
So the issue for me in the Elon Musk case, is that so many people are willing to jump straight to the conclusion that it was premeditated and intentional to recreate a Nazi salute (perhaps with some level of plausible deniability). That's important because it would indicate that Elon Musk feels sufficiently emboldened to make fascist gestures in the open. To some extent this is independent of whether he himself is literally a Nazi sympathiser or white supremacist (maybe he is, or maybe he is to some extent) - it's about whether we (or at least America) is now living in a world where people feel it's an option for them to make such a gesture intentionally and get away with it.
I personally am not convinced that we are, because for me it is not at all beyond doubt that what he did was intended to be read in the way many are keen for it to be. There is loads of precedent for him doing awkward and odd stuff on stage, it's part of his personality.
It's getting too close to conspiracy thinking for me, to assume without any doubt that what happened was someone openly demonstrating their fascist sympathies on a stage that half the world was viewing, and therefore that's the world we are now living in and we are watching a repeat of the rise of the Nazis.
Just like deciding that Father Ted has been emboldened by the state of Craggy Island society to openly declare himself a Nazi and intimidate the island's Chinese community. No, that's not what we were watching, we were watching a bit of an idiot getting caught in an unfortunate happenstance.