The question the TD needs to answer for himself is whether the call the player already made "could well have been influenced" by MI. If so, the player may change his call. If not, he may not. So the further question is can the TD determine that without looking at the player's hand? I think he can the answer depends on the nature of the MI, rather than the player's actual holding. In this case, for example, the information that 3
♥ also showed
♠ might well deter a player from bidding
♠ himself. However, that doesn't matter at this point. The only call that can be changed is opener's RHO's l
ast pass, and that only if the pass was deemed to have been influenced by the MI. Also, the explanation is UI to the 3
♥ bidder, so the TD needs to consider whether he had a LA to 5
♦ (assuming he bids it on the new auction). That depends on what he has in his hand, but of course the TD will not look at that until after the play is concluded.
IMO the facts are these:
1. Opener explained his partner's 3
♥ call as showing hearts and spades.
2. Responder, at the end of the auction, and before the opening lead was faced (or chosen?) called the director and informed him and the players that in his opinion the bid showed both minors and spade shortness.
3. Opener's RHO averred that he would have made a different call had he had the correct information.
Opinions:
1. Opener's RHO's last pass is unlikely to have been influenced by the MI. It's more likely to have been influenced by the fact the auction is at the six level.
2. Responder has UI from his partner's (mis)explanation.
3. Responder's correction of opener's MI is AI to opener. In the play, this won't matter unless the opening side become defenders (which I consider unlikely).
Relevant Laws:
Quote
21B1{a}: Until the end of the auction period and provided that his partner has not subsequently called, a player may change a call without other rectification for his side when the Director judges that the decision to make the call could well have been influenced by misinformation given to the player by an opponent (see Law 17E). Failure to alert promptly where an alert is required by the Regulating Authority is deemed misinformation.
Quote
16B1:
(a) After a player makes available to his partner extraneous information that may suggest a call or play, as for example by a remark, a question, a reply to a question, an unexpected alert or failure to alert, or by unmistakable hesitation, unwonted speed, special emphasis, tone, gesture, movement or mannerism, the partner may not choose from among logical alternatives one that could demonstrably have been suggested over another by the extraneous information.
(b) A logical alternative action is one that, among the class of players in question and using the methods of the partnership, would be given serious consideration by a significant proportion of such players, of whom it is judged some might select it.
Quote
16B3: When a player has substantial reason to believe that an opponent who had a logical alternative has chosen an action that could have been suggested by such information, he should summon the Director when play ends. The Director shall assign an adjusted score (see Law 12C) if he considers that an infraction of law has resulted in an advantage for the offender.
Quote
73C: When a player has available to him unauthorized information from his partner, such as from a remark, question, explanation, gesture, mannerism, undue emphasis, inflection, haste or hesitation, an unexpected alert or failure to alert, he must carefully avoid taking any advantage from that unauthorized information.
My ruling: "Opener's RHO may change his final pass if he so desires. If he does, the auction proceeds normally from that point, but the responder should keep in mind his obligation not to take advantage of any inference from partner's misexplanation. After the auction is over, play shall proceed normally, with the same caveat to the responder during the play. If, after the play, the other side considers that either player of the opening side has taken advantage of UI, call me back".
I think I've got it straight - and now I have to go.