It's contextually a lot different though. In this case, it's not that he didn't have an answer or a means to clarify, it's that, based on her initial reaction, he didn't have one he wasn't sure would dig a deeper hole.
I doubt anyone out there will have a similar visceral reaction to discussing code architecture.
I disagree. I can think of many ways to clarify the remark in a manner that I personally wouldn't see anything wrong with. At the same time, I can imagine a person intent on outrage finding a reason to be mad about any one of them. I generally assume that people I'm engaged with professionally aren't looking for opportunities to be mad.
Its subjective. Personally, I don't think it's reasonable to become upset by a single comment, made with good intentions, as happened in the story, certainly not upset enough to want professional consequences for the other party.
Even a single comment made with ill intent I don't think would push me all the way to pursuing professional recourse, not without me trying to 'fix' things on my own first.
I doubt anyone out there will have a similar visceral reaction to discussing code architecture.