I did not see a sexist subtext, where I think I would have seen a discriminatory subtext if he had used "I once had a civil argument with a German," because "woman" in this case explains his later pronoun use. If the person had been a man, I would have expected him to say "man", rather than "person", to better clarify his later use of "he."

In retrospect though, I can see why other people would interpret it as having a sexist subtext.