nige1, on 2014-September-08, 21:36, said:
It might be fairer were the rule that South should explain to opponents why he called the way he did, at the end of the play, or even better, at the end of the auction.
I agree that in this case it might put have the opponents at ease if the TD had said why he had found that there was no issue, e.g. "it was a mis-pull", but the idea of explaining why you have bid the way you have at the end of a hand or auction seems very odd to me. The latter sounds a great deal like being required to tell oppo what is in your hand before they lead and the former will almost certainly be construed as gloating if the explainer has done something accidental or offbeat that gained.