Hypothetical case --
I am within my year of saying kaddish and am on a business trip. I am in a very small and unfamiliar shul waiting for a minyan and in walks someone from my town who has been placed in seruv to a degree that he should not be counted in a minyan.
What is my obligation in terms of "telling on him" if it will (might?) destroy the opportunity for davening (b'zman) with a minyan and my opportunity to say kaddish. Are there mitigating factors or other variables which might guide my (in)actions?