Funnily enough I've just been looking at that thread.
I met with the most strident and extraordinary assertions that it is 100% possible to identify a male from a female on the basis of physical characteristics
Your opening gambit in that argument was that we can't tell what sex someone is unless we know them and have seen them naked and probably not even then unless we do a genetic test.
Posters pointed out how ridiculous that was, there was some discussion about how some people, mostly women, are better at correctly identifying sex than others, there was discussion of face blindness and whether this affected the ability.
You then came round to agreeing with the majority of posters who said that 99.99% of the time we can tell.
But a couple of pages later you claimed that people had repeatedly said we can always tell, which seemed a bit goady and not true.
One suggestion made and supported was that females are defined by an ability to give birth!
Within the context of a discussion about male and female physical sex differences, and especially the Q angle of the pelvis and femur, a poster said that women have the kinds of bodies that can grow and birth humans. Which is true.
You misinterpreted this and said that the poster was claiming the definition of female is having an ability to give birth.
Four posters corrected your misinterpretation and clarified for you that a female body is one which is formed around the function of producing large gametes, carrying a pregnancy etc. whether or not an individual woman can or does do those things.
Yet here you are, repeating the claim again. Disingenuous much? 