I didn't recognize the name, and I've seen the movie Milk, listened to multiple podcasts about him, and have posted on this forum for (sigh) almost 18 years.
And I would assume that White would have been more obscure in 1991 than he is now, as Milk hadn't been lionized yet then.
Carlson is from San Francisco, even though he later lived somewhere else, he almost certainly knew who Harvey Milk was in 1991
Trinity College is not very big. 2000 undergrads, perhaps less in 1991. Did any other students list their affiliation with the groups?
Carlson was born in San Francisco. He and his father moved to La Jolla when he was 7, and his father was working for a TV station in LA even before that, so he likely lived there.
Carlson attended a school in Switzerland before being kicked out. He then attended a prep school in Rhode Island.
It was probably a goof.
