Doing a Nazi salute while very Nazish doesn't not necessarily mean he is a literal Nazi. However, the optics were something to behold. It was a Nazi salute, to include all of the pomp, and done in a political setting with a crowd by an oligarch. It's not a great look.
The other ones that people are using as false equivalencies lack the pomp, they don't have the strong movement to the chest, and the sharp snap into a Nazi salute.
I wonder if you guys would have believed them if they used the excuse that liberals hacked the livestream and put in a deep fake of Elon doing a Hitler salute for a few seconds. It isn't out of the realm of possibilities that you guys would believe that if they went that route.