Overcalling your hand?

[vhawk01]

A situation came up at Caesars AC this weekend that I thought I was familiar with, but everyone else at the table (dealer included) seemed to disagree with me, although the dealer was far from certain. A quick google search didn't help, so I'll ask you guys.

Pot is heads up, river action goes bet/call, bettor tells the player "I have a straight" and the caller goes "Thats good" and mucks. The bettor then flips over 9 high (to be entirely honest, as soon as he overcalled his hand, he told the guy he was joking and stopped the dealer from killing the hand, so he did not win the pot, it was more of a joke than an angleshoot, but imagine for the purposes of the thread that it wasn't). It was very clear to everyone that the guy knew he did NOT have a straight and was intentionally overcalling his hand. What, if any, is the punishment for this?

I'm well aware that the caller has a responsibility to protect his action, but I was nearly certain that overcalling your hand was against the rules (and not just an angle). What I expected to happen was essentially nothing, the guy gets a warning about angling, the caller gets a lecture about being an idiot and protecting his action, and if the bettor does this habitually he is asked to leave.

Am I way off? Is this seriously something that is entirely within the rules?