Sjoerds, on 2012-December-15, 15:55, said:
My mistake, actually it might be a violation against Law 75B.
The Nederlandse Bridge Bond decided that the TD should rule 75B if a partnership is younger than 1 year, or when they are playing a convention shorter that 1 year.
Interesting. I'm not at all sure that this regulation, if that's what it is, is "not in conflict with these laws" — see Law 80B2(f).
Without looking back in the thread to see what evidence we have in this case, I think generally the TD is to collect what evidence he can find, and to rule on the preponderance of that evidence whether there was a mistaken explanation or a mistaken bid. The law's admonition that "the director is to rule mistaken explanation rather than mistaken bid in the absence of evidence to the contrary" isn't really of much use — if all the evidence says "mistaken explanation", then of course you rule that way. The only way this admonition makes sense is if there's no evidence at all, either way, and that should rarely if ever be the case.
If, using the 'transfer over 1NT' example in law 75, the partnership is new, or their adoption of transfers is new ("less than one year") that's certainly evidence worth considering, but if both players have on their system cards that 2
♦ is a transfer, I would give that more weight than the "age" of the partnership or the agreement. IOW, if the responder intended 2
♦ as a natural signoff, he misbid. His partner did not mis-explain. Whether I would make the same ruling in the instant case, I don't know. I'd have to go back and reread the thread, and I'm too tired to do that right now.