I mean, no, he didn't get it right.
However, he's a baby, in the scheme of things. He's seventeen (or thereabouts). I have known boys that age. That he thought to ask at all is pretty monumental. His phrasing upset your daughter, and if you sit there and pick it apart (he asked your daughter's "owner" instead of her, he didn't offer he questioned your DH's treatment of her, etc) of course he doesn't come off particularly well.
But in terms of anti-feminist sentiment, there are so, so many more worse ways this could have transpired. He could have stood at the bottom of the stairs and laughed at your DD, elbowing your DH to get him to laugh with him, saying something like "ahaha look at her waddle" (I'm sure she doesn't, but boys can be stupid in their humor). He could have ignored the situation altogether and lazed on the couch and asked for a cup of tea (despite plainly seeing the others working away at the unit building).
What actually happened was, his teenage, rudimentary, best-behavior inner monologue likely said something like "WORK BEING DONE. CHANCE TO HELP" and his mouth engaged before his brain caught up. Or, maybe he just hasn't yet been educated in the nuances of benign misogyny.
Your daughter rowing him over it isn't going to teach him. It's far more likely to have the opposite effect: they'll break up because he doesn't like being shouted at for what he thought was being nice (and why should he?) and he'll be back in the dating pool of teenagers with some less than flattering opinions about self-identified feminists. And we have enough men in this world with less than flattering opinions about self-identified feminists.
I'd suggest that you suggest that she calls him up, apologizes for going off on one, and has a calm and reasoned conversation about why she was upset. You can stress that it's okay that she was annoyed, and that she's allowed to feel how she feels, but that she has a choice about what comes out of her mouth and she's likely to catch more flies with honey, etcetera. This is not about "the crazy woman pandering to the clueless man", it's about "the ultimately correct but unfortunately volatile girl apologizing to the ultimately wrong but unfortunately offensive boy".