It sounds like the person(s) who took offense did so because Trump supporters were being called Nazis. The problem for them is that the person who was fired was talking about the actual Nazis who were Trump supporters.
The dynamic of Trump supporters hysterically screaming that people are calling them Nazis, every time someone points out that the ranks of Trump supporters includes literal Nazis is getting more and more absurd as the Nazis become more and more obvious, more frequently front-and-center in Trump crowds. To make things more absurd, the two strains of Nazi defenders seem to be those who claim they’re only Nazis because liberals called them that, and those now claiming that the Nazis are actually… Antifa.