If I were Rika and if I had this foreboding feeling that something isn't quite right, that things are going too fucking good and that it shouldn't be this easy, I'd write on the instruction papers for the other club members, to do something extra, just in case. For instance: "If Satoko does something surprising, or if she shoots me, attacks me with a weapon or whatever, she wins the game. Please stop her." Remember, they have to do what she tells them, it's their punishment. Although it isn't absolute or anything, they aren't, or shouldn't be, loopers, therefore they'd likely oblige. Unless it's more of Rika being Rika, in which case we'll see her brains or guts again in the next episode. Either way, show's really fucking fun.