Sounds like you never really liked feminism in the first place and found an excuse to justify it later.
Further, at the time this happened, I didn't even know what feminism was. I was around 16 years old. It was 1978 or so. After it happened, I did some investigating and discovered what might cause such a reaction. For me, it was plain that it was a philosophy based on false premises and as such worthy of rejection. I don't go about preaching my position, but I also certainly never even silently consent to the approbation of a false idea.
Here's the real kicker: tell me what feminism is, then we'll see if we agree it's a good thing or a bad thing. (Of course, the debate on what feminism is will never reach a conclusion, so we're unlikely to get to the second part.)
I would also probably have held the door open, as I was taught that was the polite thing to do.
And she probably would have yelled at me the same way she did at you.
But as the old, fat, white American guy in the room, I wouldn't let her problem in this area change me for the worse or otherwise bother me.