Showing a player a rule.........

[officialtony]

No No No No No.
Hopefully that is clear enough to state my opinion.
Let it be. If he did look, he knows he's wrong and you don't need to put salt in the wound. If he didn't look, then it is forgotten and you don't need to open old wounds. As was said, you are looking for trouble if you do it. You can't teach these guys " new " info anyway. They are adults and should know already - or at least their coach should.
OK, I've said my piece.
My humble opinion.