The common parlance is very problematic. Anyone can see it is in fact a conspiracy theory, but if it's true, you're not supposed to call it that? How would you know?

Using conspiracy theory as a derogaratory term is a form of doublespeak that shield the conspirators and their conspiracies.

I, for one, will not stop calling conspiracy theories conspiracy theories, regardless whether they are true. Actually, especially when they are true.