Exactly, he's projecting his own beliefs as absolute truth, nobody else is allowed to speak the word truth lest they 'conflict' with his own inherently conflict based logic definition of the word where he knows the truth of things (such as the word truth used by others as necessarily being condescending).
By his own inconsistent logic he is claiming his statements as truth and not truth at the same time.
This is what the dialectic logic looks like in conversation.
The dialectic logic mind will demand to 'control' both sides of a dialectic set, with one projected onto the other guy, "you said the word 'truth', therefore one side of my inconsistent dialectic thought is now your thought, and I also control my thought on what I think the truth of the word truth means that you're supposed to obey as well".
Nowhere in the guy's accusations is he even recognizing the speaker as an individual human being who just like everyone else, INCLUDING THE ACCUSER is depending on SOME axioms and methods to even make any claims to truth about the word truth in the first place.
The way to nullify these accuser's projections is to describe everything they are accusing of you, as their own psychology that has nothing to do with the speaker.
Narcissists get scared and lost as that happens because they need and depend on trusting compassionate victims to obey their dialectic logic (you're anti X, whereas I am pro X, I win".