All the guy had to say was in re enactments, someone has to play the bad guys. Tough to have the event if hundreds of people plays the good guys shooting and chasing one bad guy across the field.
Cantor is Jewish. I highly doubt he is a Nazi sympathizer.
A short list is here:
http://listing-index.ebay.com/actors/List_of_actors_who_played_Nazis_in_movies.html
Curiously, the Wikipedia list was taken down.