That's correct. It's the coaches fault. Don't demean the players by making them live thru a silly stunt like that.
Now, if the coach wanted to make the players STAY after the game and have a spontaneous practice session, I'm okay with that. Why? Because it's constructive, and the players might actually learn something from it. For example, maybe they had just played poorly against a defense that they don't see very often. Therefore, going over it immediately after the game might be a good, constructive way to address it while it's still fresh on everyone's mind.