It doesn’t say that the TW ever exposed her penis.
”An employment tribunal in Leeds was told that the transgender woman — who cannot be identified – was quizzed by a manager about her underwear after concerns were raised that she had been naked from the waist down in the women’s changing room.”
But it also says
“And on the same day, the employee said she was subjected to “deeply offensive and unacceptable” abuse while in a changing room cubicle, when she overheard a discussion between two female colleagues. The tribunal noted that one colleague said that she was “sick to death of this bloke with a dick pretending to be a woman, who doesn’t even dress like a girl and has facial hair, that thing may rape me and we can drive it out of the department and maybe find a suitable leper colony for it”. Later, the transgender woman said she again found a note in her locker saying “get out tranny”.
So the TW used changing cubicles to dress and undress. She couldn’t identify the colleague that said the above because of the cubicle walls/no line of sight. The changing room also had a shower so likely the TW had a towel wrapped around her between shower and changing cubicle.
If the concerned women had seen her penis, why didn’t they say so? Surely that’s more to the point and damning than saying vaguely “naked from the waist down” which is also true of anyone simply in a towel as they aren’t dressed.