The theme throughout Kaiji has been that there are two types of people: those who use and those who get used. Kaiji isn't using anyone at this point, so we can assume the game is rigged and a few of the members are using him (this is Kaiji, that much should be assumed from the beginning). Also, the guy sitting next to the leader became a little upset when the new guy wanted to record the rolls in his book. It's likely that he's in on it with the leader.