Table Result NS +620 or -800 depending on how you rule.
West commented, "Everyone seems to have diamonds" on this deal from a North London club last night, and South immediately stated, "I did not mean to bid that, I meant to bid 4H". The TD was called, and South was asked by the TD which call he intended to select when he reached for the bidding box, in line with potentially faulty EBU County Director course guidelines. South admitted that 4D was not a "mechanical error", and he could only suggest that he was lured into bidding diamonds "because everyone had", but 4H was his "intended" bid. Somewhere between him making that decision and his withdrawing 4D from the bidding box, something went wrong and he selected the 4D card. He had heard that one was allowed to change "brain-error-bids" in Holland, and he wondered whether the new liberal approach, that seemed to be prevalent with insufficient bids, also applied in England to errors of this type.
SB, East, thought that South had "intended" to bid 4D, and North would now bid 4S. South could go back to 5H, but North would interpret this as a slam-try and sign-off in 5S, doubled by East for +800 to EW. He was happy to run through the play for the TD if he wished, but the TD told him not to make his own rulings again. How would you rule?