I personally didn't see what he was doing as purposefully transphobic. Insensitive? Downright.

But I actually think he explained pretty well that he wasn't intentionally transphobic to you. This doesn't negate the damage that was done, but I think pointing a finger and accusing him of purposefully being malicious in that way is pushing it a bit. Again, I don't justify what he did, but I don't think it was purposeful the way it's being talked about. Even in his original post it talked about color palette mostly? You're allowed to take back the design and take ownership of it, but saying someone else designed it as if he didn't is where the questionability of picking a fight comes in. I don't think you're being intentionally malicious or even confrontational, but I think that you should possibly do some self-reflection about if you're doing things subconsciously out of pettiness and such. I don't invalidate the trauma that happened to you, I'm just offering another perspective.