Hi, Skyler!
I'm afraid I can't answer your question since I live in Ireland. But I find your post very interesting. This of course isn't the first time I've heard of a transguy being refused the use of male facilities--the loo, a changing room, whatever.
Now we T-girls often run into opposition about using female facilities on the grounds that we're a threat to women. We're "perverts", "sexual predators", etc. Now if this were truly the reason that people don't want us in the ladies' room, then why the opposition to transguys in the men's room? Does a cisguy really find a transguy a physical threat to him?
In other words, what we're all faced with--guys and girls--is simply a general dislike of transpeople. Physical threat or no, they don't want us being what we are. Hence their insistence on segregating us, if, that is, they're gracious enough to tolerate our existence in the first place.