I think that you actually understood the point perfectly! I'm a native english speaker, and to me, it looks like he is trying to raise the exact ambiguities tha

I think that you actually understood the point perfectly! I'm a native english speaker, and to me, it looks like he is trying to raise the exact ambiguities that you are asking about. I don't think that his statement is meant to be an answer, rather, I think it's meant to be a statement to jump off of. It's bringing up how definitions matter, and that in different contexts the answer to the same questions could be yes or no.