Me: I think you may have the dates entered wrong. I just looked up the policy on the mainframe and the effective date is listed as 2001.
Them: Nope. You're wrong.
Me: Ok, but I'm looking at it right now and what you've entered doesn't match.
Them: Then dumbass must have entered it wrong.
Me: ...
Them: Yeah the dates are wrong.

It doesn't always feel good to be right. But sometimes it feels good to be right.