To the questioned:When expressing a view, being questioned feels like a challenge. For me, it feels as if the other person doesn't believe me and is trying to catch me in a lie. Frankly, maybe I did embellish a bit. Maybe I made a statement based on something I thought I remembered hearing but don't quite remember where I heard it. Or maybe I feel the statement is so obvious, the only reason someone would question it is if the other person wanted to try and take me down a rung.
It's OK. If, as speakers, we feel we are in the right, we can treat all questions as if the questioner doesn't know the answer and is seeking help learning, or there is some ambiguity in the questioner's mind and they are just trying to help clarify it. (Remember, for topics we are knowledgeable on, it is hard to see the subject from the perspective of a less-informed person.) Answer with the intent of being as genuinely helpful as possible. Have fun! This is our chance to help someone out!
And if we don't have the answer, we can be polite and say so. "I honestly can't demonstrate it right now. If you'll allow me the time, I'll collect the information for you and get back to you. And, in the event I can't, I'll let you know." Everyone is wrong at some point. Big people can admit it and only weak people don't accept it from others.
And to the questioner:Be aware that you may be unintentionally putting the questioned person in an emotionally defensive position. They may have all the answers and be able to clearly explain it. They may be right, but need time to collect the evidence to demonstrate it. They may be flat out wrong but not prepared to say so.
Be a good participant in the social dynamic. If the other person can't answer, is evasive, or is demonstrating some technique to avoid answering, give them an out. Say, "It's OK, let's pick this up again later." Or "If you find/remember the answer, please message it to me." If the question is unimportant to you, you lose nothing by letting it go until the questioned person brings it up to you again. And if it is truly relevant to you, you can look it up yourself. If you feel you can't let it go, ask yourself if you're truly practicing the principle of charity.