-A8
To what "reason" are you refering? How does it differ from gratuitous assertion?
If you think the assertion is false, then simply state that it "begs the question". I suspect that's what you were trying to say when you said "non sequitur".
I don't think the assertion is false. I think it answers a question I did not ask.
What would you call it if I asked for your phone number, and you gave me a "home team" cheer?