This was always going to happen.
It's a point that's come up quite frequently over the years. That if a man is standing there, and all his documentation says he's a woman, as does he, what are you supposed to do?
Fortunately, now, the guidance says you can still tell him to sling his hook.
And, of course, there IS no other way to deal with this.
They've just made it completely okay to forcibly exclude someone, based on visual evidence.
It's the only possible recourse, if documentary evidence isn't relevant.
And they can't even take you to court. Because then, the real sex of the person will come out.
And if you are actually wrong, they've clarified that it's not discrimination.
Job done.
It's all along the same lines that if a woman identifies as a man and frightens the women in the changing room, because she looks so male, you can exclude her.
They really are closing all the loopholes. Snapping them shut, in fact.