I love it when people call me a liar when I happen to know more about something very specific (that happens to fall within their field of study) than they do.
I'm done with these people.
When someone says something that I don't think is correct, I say "I'm not sure about that" and ask questions which elicit info I can research for myself.
I don't call them a liar and say things like "well I have a PhD".
Shove the credentials up your ass.
Sorry, but bananas are berries.