I agree, now that I think about it. Claiming the reward is based on winning the game, but the payout is due to a bug (which the casino is not aware of) and not a win, so it is a deception (fraud).
When I was a teenager, an ATM once reported my checking account balance had a few extra thousand dollars in it. Withdrawing that money would be fraud, even though it was a computer error. Luckily I was not a stupid teenager and I left it alone. The next day it was back to the correct value.