Maybe, just maybe, he put Grayson back in to force him to deal with a bad situation that he had just created. I have no idea why K put him back in. Maye it was an attempt to force him to control his emotions. Maybe that is a stretch, but do you really think that K put him back in to save the day for Duke? Do you really think K put him back in because he thought he needed Grayson to play to win that game? Maybe, just maybe, it was a teachable moment.