Is this person justified or a jerk?

I don't have a problem with being closeted at work, sometimes this is totally necessary. Even if you're an activist, I don't think it's fair to expect one to have to risk their job and thus their financial security (and potentially their happiness) by divulging more about their sex life than is really anyone's business.

That aside, I do think he's a jerk because the Human Rights Campaign is a transphobic organization. They do not support equal rights for people who are variant in gender expression. Ultimately, this excludes a large percentage of the gay and bisexual population, so one could convincingly argue that HRC is actually homophobic. Additionally, they have appropriated the phrase "human rights" and made it only apply to gay rights. This is disrespectful to every person who is denied their rights because of their race, gender, economic status, immigration status, etc etc. Basically, no self-respecting gay or bisexual or queer person should be contributing in any way to the HRC.