The agent acted with second intentions. He knew the gambler was avid to play and that he didn't have more money left, but at same time he saw on this an opportunity to trap the gambler into a long term debt with the local casino. Ethically he is wrong, because he took advantage of someone vulnerable, although for the law it means nothing. It's still the gambler's fault to have accepted credit. It was a conscious decision to accept credit and now he will have to pay the consequences for his choice.

I really don't know if he will manage to earn the money somehow to re-pay the casino. Probably he will have to ask for help from family, friends or even the local bank, otherwise we don't know what the agent can do against his physical integrity... It's a very serious situation he finds himself in and I've already seen many people who were murdered for not paying their loans back.