Maybe it is “know” and is short for something like, “I acknowledge that you have requested information, and I feel that I have the necessary understanding and knowledge to answer it.” Sort of in the way that “my bad” means “I have erred in my duties to respect etiquette or the performance of some task with which I was tasked; please accept my deepest apology.”
Perhaps through life experience your friend has learned that it is best to categorically deny every request, as it helps to prevent others from running off half-cocked, spreading havoc pell mell across the country side.
One time, at the university library, as we were waiting for a ride, a woman approached us and asked, “Were you guys up on the third floor?” “Yes,” we replied. “I am not a dyke!!” she shouts at us and charges into a long, screaming monologue about how she can run the four-thousand meter in such-and-such time and that not all atheletes are dykes. Sobbing and in tears she ran from the lobby, hopefully soon to feel the benefits of her cathartic outburst. Interestingly, while we were on the third floor, we hadn’t seen her, nor had we talked about women, sports, or dykes. “Categorically deny everything,” was what one of my friends concluded.
That’s a true story.