Surely the man was saying almost the opposite of that, Lonesome - he was ponting out a case of a man who was assumed to be Jewish, on account of the way he looked, but evidently isn't. (I suspect in fact the assumption might be as much because of the character with which Michael Richards was associated - without that, and if he used his mother's maiden name, Nardozzi, I suspect people would say he looked typically Italian.)

I know however from daily experience that there are plenty of people whom I meet in my life who I identify as probably Irish or Polish or Filupeno or Jewish, or whatever, on the basis of their looks, and most times when we get talking I find I'm right. It doesn't mean that all Irish etc people look the same, just that there are certain (very different) looks that tend to go with being Irish etc.