It’s ok to question Irish - particularly when Scientists or Politicians claim to be stating fact (regardless of the topic). It's ok to take mindful care when reviewing evidence before drawing conclusions. I think you understand the ramifications of not doing so.

That's why one seeks a second option in the case of a brain tumor. It's not denying that the tumor is real. Its doing due diligence to get a variety of opinions before drawing any premature conclusions as the best course of action to take. It's not hubris, its being mindfully intelligent.