I don't think it is, it's wearing a modern cav helm with a mic. Nazi aren't the only military to use a skull, you can find similar insignia on just about any modern military.
I would think that maybe accusing a literal rabbi of being a nazi, based solely on your perception of military insignia.....just might make people question their understanding of said military insignia. But I guess expecting Americans to contemplate historical context is a big ask.
There are of course neonazi fighting in ukraine, but it's a relatively small amount of people on both sides. The Azov legion is only 900 people, out of which you probably have several dozen hardcore nazi, and the Russians have several dozen nazi in the Rusich group in Wagner pmc.
To claim nearly a million members of the Ukrainian armed forces are nazi because a rabbi is wearing a skull insignia is just as crazy as claiming all pirates are proto nazi because they ran the Jolly Rogers.
I'm not really familiar with nazi symbols, but I'm pretty sure it's not how it looks and should look the opposite way. The design is really similar though, so I'm not sure. Maybe they had different styles over the years?