I am glad you shared your story. To be honest, I think your response to that patient was the correct one. He may very well have had raw wounds. That doesn't make his racism OK but I understand how emotional dysfunction needs to be worked out. Unfortunately many people don't, so they continue to take it out on innocent people.
I am simply angry about the people who said "Hey Chinatown" or "Ching chong" to you or the guy who made the comment about giving jobs to non-Americans. Hello, you ARE an American. You also seem like an incredible doctor. Your patients are privileged to have you.