"I was scared for my physical safety"
If true, he could've called for help. Lord knows that there are more cops than sense in airports these days.
If he'd really wanted to protect himself and screw the Nazi over all he had to do (bearing in mind he was at an airport) is point at the Nazi and scream, "He might have a gun!"
75 cops would've appeared out of nowhere, blew the hell out of the Nazi and then asked the Rabbi if he was okay while they planted a drop-gun on the Nazi to make the story stick.
I exaggerate, of course.
But when have you been in airport lately when a cop wasn't within earshot?
Sorry. The Rabbi had better options than throwing coffee in the guys' face and then apparently sucker-punching him while the Nazi has the coffee in his face.
That's what I would have done.