Sometimes people can just be brutal online. Gay or not. I try not to let anything that happens online bother me. but depending on how much of one's life is spent online, that can be hard.
For me, it's always surprising (even though it shouldn't be) when a gay (or other sexual minority) is being... a dick. I just feel like asking, "You're gay (or w.e). Don't you know what it's like to be oppressed? To be discriminated against? To be insulted again and again? Knowing what that feels like, why would you want to do that to me (or anyone)?"
But I don't ask that. I know nothing would come of it if I did ask that.
I think that gays (or other sexual minorities) are just like normal people. They have their own issues that don't necessarily have anything to do with their sexual issues. You know, maybe he was in a real mad mood that day and didn't believe anything he was saying to you but just wanted to be a dick to make himself feel better. I can understand how that must feel, how when you're pissed off you just want to hurt things or hurt people. Like the saying goes, "Misery loves company." You want to make other people feel miserable and bring them down to your level.
And even if he did (somehow) truly believe what he said, I just try to not to let anything anyone says hurt me, but particularly if it's a stranger. I just try to put my hands up, walk away, and say (to myself) "He's got issues."
It's also possible for even a gay person to be just SO misinformed about trans issues that he honestly doesn't have a clue what it's like to feel like the opposite gender. but it doesn't sound like this is the case with this guy, because of all the "choice" words you said he used. That stems from "issues" as I like to put it. Whereas pure naivety would just be confused and perplexed at the thought of wanting to be the opposite gender, but there is no need for insults when you're just perplexed. So I think he had something else going on.
