It's like teaching Christianity, but other people saying well he's never actually said Jesus is the son of God.
There are a fair number of modern Christians who would say Jesus isn't the Son of God, even if many also would say that hardly counts as Christianity.
I'd not be comfortable with assuming, in a written context, that Drummond believes that not being sexually interested in trans persons is bigotry. I would not be surprised if that is the case, in fact if I were inclined to gamble I'd bet on it. But there are people who would argue that male born people can be "lesbians" but are not willing to police sexual attraction. If you want to say, in print, someone thinks something, you need to be able to show they've actually said it, not just that it seems to fit in with what they believe.
I would not be at all surprised if Pink News knows that he does think that way, but as long as there is no record of it, it's a bit of a gift to them to make the claim.