"After a several minutes later, a security guard showed up with one of those big clear/acrylic chip carrying case/box (which was empty). He had them put that single chip in an empty chip rack, they put the rack in the empty chip toting box, and away he left. Poker dealer told me I should have just picked it up and kept it."

The law states:
If you turn it into the security desk and put your name on it, wait 30 days, no claim on it, its yours.

I've done that several times, one time it was $300 and a lipstick in a little purse with no ID in it.