Define sex being identified correctly? Is that on genetic makeup, external genitalia or what? I don't dispute your figures by the way. Anyway, my point was those arguing against Astrosloth saying gender isn't always binary were clearly talking bollocks. Or perhaps that should be ovaries.
I haven't read the whole thread so apologies if I'm repeating others but Astrosloth is spot on.
Intersex is a term which roughly describes sexual/gender ambiguity. Gender can be defined in four ways biologically (I think) - I won't bore you with the details but it can be done at a genetic level...