Yes, it was uncalled for and rude.
I agree with most posters: a trans woman is male and a trans man is female.
However, the partner of Vicky Thomson, let's say, no doubt considers her a woman (ie gender identity based view). Therefore he may well see himself as a straight man.
If he self-described as bisexual, that would imply he'd be quite likely to be attracted to a non-transitioning male.
My original response to boopsy was on this kind of basis. I do completely agree that most lesbians (and straight men) are unlikely to be attracted to bepenised persons. And as said above, any attempts by bepenised persons to claim discrimination for lack of attraction are a load of entitled twattery.