Maybe she just wants to be mad.
We have a winner!
This could also be a place where you might want to try and "agree" with her instead of just validating.
Fairly harmless... .even if the engineer in you could explain it another way.
I do sometimes "hold the line" or even "push back" when there is a suggestion that I am responsible for something that I'm not... .especially if it has to do with "design" or "thinking something through"... or "reasoning".
Many times I'll say "Ohh... .are you asking how I decided to do it that way?". If there is further blather then I'll ask her to let me know when she is ready to listen and I depart to do something else.
There is really no "fix" for them being mad and wanting to express it... .I've been able to get it down to a more manageable level where walking away usually handles it.
FF