Yes, but be careful. Reputations take a long time to make... and an instant to destroy. So be sure that you didn't build him/her up in your own mind and that he/she merely over represented him/herself. But if it was a blatent lie (and as you say, he admitted his prevarication to another person,) then you owe your community at least the facts as you saw them. Avoid hyperbole and exaggeration.

It's your reputation too. If you come off as an emotional wreck, the only person you'll hurt is yourself.