And then they get mad because you humiliated them in front of all those people, and carry a grudge about it and say you're vindictive and "have to be right about everything."
"You were very confident and I doubted my memory. I wanted to make sure I wasn't spreading misinformation."
One of the quickest ways to deflate the person's argument, especially in a social setting. It makes you look humble and makes them look like an asshole if they keep going at it. If you want to subtley needle then, you can also apologize if they felt attacked by being corrected.
this. its like two types of people. I will never say anything is for sure. If I say 99% sure that is about the top for me. I recognize that there could be something untrue somewhere in my statements but I know other folks were if they are over 50% sure they definately know.