When I play a multi-player game in real life, I try to clear up the contentious points before the game starts.
What is important, with the card Today's Special!, is to choose to play 1, 2 or 3 cards before drawing the 3 cards.
A player can not be sure to make the best choice when he decides to play 3 cards or even 2 cards without knowing the 3 cards he will draw. So I don’t think it’s necessary to ask him to justify his choice, because it would be a disproportionate inquisition to the objective of not giving him a very small advantage.