I think it's important to recognize that he still assumed some risk with each spin. That risk was reduced from 1/6 to some much smaller number, but the risk was not zero. His concentration or timing could fail on any given spin, as evidenced by his final spin where he mistimed it but got lucky.

My point is that I don't think you can say he was cheating. He played within the rules of the game and couldn't just drain cash out of the system forever.