"I am very suprized they let Jim walk out of the casino with a $5,000 chip they knew he did not own. They had every right to take."

Now I'm confused. I understand a casino's right/obligation to investigating paying at the window for chips redeemed of a large value, but I don't understand how the casino could keep a live chip after it was offered for redemption and at the same time refuse redemption. I could see a casino confiscating a counterfeit and having someone arrested, but that's not even close to the same scenario. If they can't prove it was stolen, from them, they'd have to chose between cashing it or giving it back to the person trying to cash it. Saying Jim didn't own the chip is an assumption. Saying he couldn't redeem it is a fact. Saying the casino could confiscate it after it was presented for redemption under these circumstances is surprising. It'd also be very wrong in my opinion.