I'll ban myself if this gets into a Pol discussion, but it seems pretty clear that there's a sane interpretation and an insane interpretation:
Sane: The coach is not a nazi, but accidentally held his arm in the position of a nazi salute, then laughed at the coincidence with Hendriks after it was pointed out to him .
Insane: The coach is a nazi who decided to out himself to his co-workers with cameras running.
Almost everyone in the twitter thread believes that he's a nazi who should be fired immediately.
Social media was a mistake.