Well, I have to realise I've only heard one side of the story, so a perfectly objective comment is impossible.

But based on what you said, I can relate to your position completely. I always try to be polite to strangers too. The only exception is teenagers who think they can get me to buy alcohol/cigarettes for them. But I'm polite to everyone else.

Based on your post, the old man clearly recognised his superior position to you (in terms of political correctness), and knowingly abused it. So you have my sympathies.