Some say there is no such thing as absolute truth, and then are asked if that statement is itself an absolute truth. Is this a grammatical ruse not touching ethical relations and relativism?

This text is from a transcript of a talk by David Gooding, entitled ‘God’s Power for Salvation’ (2005).

Well, you have heard correctly: they do say so. My argument (it's not just mine) is this. If somebody says, 'There is no such thing as absolute truth', what he is saying is a statement of universality, is it not? 'There is no such thing as absolute truth, nothing is absolutely true.' Well then, if he says that then he is making an absolute statement. You are right to then ask: 'That proposition that you have just enunciated—"There is no such thing as absolute truth"—is that true?'

And what is the point of pushing him to that? Well, because if he replies, 'Yes', now he is making a universal statement. He is saying there is one absolute truth, and that is that there is no absolute truth; and it is universally true throughout the universe—there is no such thing as absolute truth anywhere at all. Well, he is laying it down as an absolute truth that there is no such absolute truth in the universe. It is the 'self-referential fallacy' in logic.

Is this a grammatical ruse? No, it isn't a grammatical ruse; it is a logical fact; it is a logical principle. If the man said, 'There are very few absolute truths,' that would be one thing. But to say there are no such things as absolute truths is to state a universal, absolute statement, and therefore in so doing he does either of two things. Either he is saying, 'Yes, there is one absolute truth, namely: there are no absolute truths.' Or else he is saying, 'No, what I said wasn't true, and when I said there is no such thing as an absolute truth that isn't to be taken absolutely. I didn't mean there was no absolute truth anywhere.' Well, which way does he want it? It is not a grammatical ruse; it is a question of logic, of what he is trying to say.