I am a doctor. I do not believe for a minute that this ridiculous young man believes most of the garbled nonsense he is saying about sex and male and female. He however arrogant enough to think that it doesn't matter if what he is saying is true or not, it's enough that he is saying it.
I do believe the GMC should become involved. Spouting this anti-science (anti-reality) risible (and far from harmless) guff, while under oath and in a very public forum, is the very definition of bringing the profession into disrepute.