Mentioning a word does not count as using it. Mentioning it means you are talking about the word itself and not endorsing its usage. You are not using a word simply by mentioning it. This distinction is extremely important in philosophy. When I say that the word 'green' has five letters, I have not used the word 'green'. I have simply mentioned it. The distinction is also important in our moral evaluation of what people do with offensive terms.
Edward Wyatt of the New York Times doesn't care about this distinction. I don't know much about the show Grey's Anatomy or the actor Isaiah Washington. Apparently he's been accused of using the word 'faggot' as a deliberate slur against someone who is gay. If so, then I agree that what he said was immoral. This word is offensive when used to describe a gay person (rather than a cigarette or a piece of split wood, which have an older history of use), and I cannot see any defense of it, even given Christian views about gay sex being wrong. Calling someone a faggot does a lot more than indicate views that the person engages in behavior you disagree with. It certainly doesn't amount to speaking the truth in love, as the apostle Paul commands Christians to do. I do not use the word in any of those contexts myself, even the two unrelated to homosexuality. But notice that I was just willing to mention the word twice.
I don't know what happened back in October, but if Washington publicly denies using the word and in so doing mentions it, it is simply bad reporting to say that Washington "publicly used an anti-gay slur for the second time in roughly three months". It looks as if the second time was not another occurrence of his using the term but rather a mention of his use of it, one that very clearly in context did not amount to endorsing its use but in fact the reverse.
I can understand how some people might disagree on whether it's offensive to mention offensive words. I almost never even mention the n-word. There's too much associated with that word for me to consider it appropriate for someone intimately connected with black people even to mention in most contexts. But clearly it's worse to use it than to mention it, and I wouldn't even consider doing that. Whatever you might think of the wrongness of mentioning this word, it's just insane to think that mentioning it is the same thing as using it. It's a little strange, then, that the second occurrence has provoked a firestorm, when the first wasn't even on my radar back in October.
For some more detailed discussion by linguist Arnold Zwicky, see his Language Log post.