1. Are in the tiny minority of people in Japan who don't speak Japanese
AND
2. Chose to switch to Japanese when Google asked them if they'd prefer Google in Japanese or English
Google guessing that she might have been Japanese was not the major problem here. The ultimate problem was her incorrectly stating her language preference. It's hard to see what reasonable measures Google could have taken to inconvenience fewer people here.
Actually, it's a problem for anyone who speaks a language that is different from the official language of the country they are in, and don't have a Google account (a lot of people.) In any case, a persistent language menu on all Google properties that has all languages available would solve either and all other problems associated with language choice.
1. Are in the tiny minority of people in Japan who don't speak Japanese
AND
2. Chose to switch to Japanese when Google asked them if they'd prefer Google in Japanese or English
Google guessing that she might have been Japanese was not the major problem here. The ultimate problem was her incorrectly stating her language preference. It's hard to see what reasonable measures Google could have taken to inconvenience fewer people here.