While that may have "fixed" the issue, you have to admire him for not taking the easy route and telling this lie.
"Fake it til you make it" works because most prejudices are kept alive because of conformation bias and herd mentality.
There's been no evidence that this position affected his work at all over the last 15 years, or the ways he may have interacted with LGBT coworkers. There's also no evidence that he fears or hates gay people.
Relationships are a complicated topic, and a lot of very reasonable, intelligent people have a very diverse set of opinions on how they should operate. Can we please stop lynching someone because he happened to hold (at least at the time) the most popular opinion?
This is the kind of thinking that leads to "gay propaganda ban" in Russia. Government doesn't care whom you love, it only cares what "children" think about you.
Disliking some group of people is pretty much ok, as long as you manage to keep your behavior civilized. That's why people are talking about tolerance and not obligatory love towards all other people.
Knowing it though and not being able to say (at least pretend) he changed his mind is disturbing for many people, because then it became part of a public image.