If there was a bit of doubt somewhere, then yes, I'd be able to see the argument of the other side. But one of the conditions is that the psychologists have 100% accuracy. With that in mind, I can't possibly see any justification for the other argument. If it were a real-life issue, then sure, free will and all that, but given that the box-givers have essentially already seen what you're going to do, there's absolutely no grey area.