Alexei, they predicted blue, that's not the same as correctly predicting blue.

Denis, that leapt out at me as well - whoever wrote that sentence isn't defining "rational" the same way I do.

Cyan, that'll be covered in a future post. Certainly in situations of opposition you will want to take actions that are not predictable to your opponent, and so you'll want to sample something as unpredictable as possible according to a known, game-theoretically determined probability distribution. A quantum device is fine for this, but realistically, so is thermal uncertainty and strong cryptographic random-number generators. To look at it another way, what you're doing in this situation is not so much being clever yourself, but rather reducing the optimization power of your opponent - certainly chaos and noise can act as an antidote to intelligence.