Not race in particular. Just identity politics. In this case, it seems one of the woman friend in my circle thought I was being sexist to her friend. We were Asians, but I didn't grow up in the US, but these 2 women do. The immediate reaction to that question must had evoked something deep within her, that I attribute to her upbringing here in the US.

You are right, but I would add another item. She forcefully inserted herself in the conversation you had with your friend, and did it in a way that changed the conversation to the worse, with the tone becoming adversarial, and the direction of the thought rather different from what the original participants of the conversation intended. When it happens to a friendly group of people (as was the case here) it is okay, the confusion can be resolved peacefully and the conversation can move whichever way the three of you choose, being friends and all. But sometimes it happens in a larger scale, and then the conversation can be destroyed. I really wish people had been more conducive to maintaining a dialogue, we need to maintain a decent level of discourse in the society (and, more particularly, in our industry).

Indeed, after that night everyone just forgot about that conversation, since we mostly know each other.

I imagine social media is the worst environment to have this kind of dialogue.