When I came home from the Military (during the Vietnam Era), a young woman spat on me and called me a baby killer. I knew she was wrong, and forgot it. No drama.
I think your response was acceptable. In the Bible, if someone unclean spat at you, you would also be unclean and would have to wash yourself and your clothes (Leviticus15:8). In the case of Miriam, when she criticized Moses for marrying a Cu****e woman, and she was punished with leprosy by...