I think he knew exactly what he was doing. He's an apartheid supporting, Afrikaner nationalist, a movement aligned with Nazi ideology. He's definitely aware of the Nazi salute. And doing it at such a prominent event, I believe, provides a glimpse at what he thinks the next four years are going to be about.
Discussion
His family wealth benefitted massively from the Apartheid regime and constitutional racism, so why wouldn’t it work now?
He’s a weirdo and a maniac.
PS: How do you like Ember?
He's trolling.