I saw an episode of Dear White People that reminded me of this situation. The black female protagonist was attending a conference to get funding for completing her newest film. She found someone who appeared to be very interested — until he found out that he had confused her with the other black woman who was looking for funding at the conference. Within the context of the story, you could feel her anger and frustration. It was the old “we all look alike“ problem writ large.

I think those who reacted to your typo were vulnerable to triggering because of encountering similar experiences. I think part of being a decent chap in the woke 21st-century is doing what you can to to learn about those kind of triggers and to try and avoid setting them off. But I also think they are going to be unavoidable to some degree, and the marginalized people should cut us some slack if we occasionally screw up. The rules are still being written, and nobody really knows what they are yet. To paraphrase Freud about cigars, sometimes a typo is just a typo.