EBU regulations.
NS is a regular, experienced partnership. EW is an occasional partnership, with no convention card. 1NT was announced as 12 - 14, the double is 15+, primarily for penalties (sorry - I didn't manage to include this information in the diagram). When asked by South, West explained the 2H as natural, showing 5+ hearts. The accurate answer should probably have been 'No partnership agreement'. Many in the club do play this sequence (1NT x 2H) as a transfer to spades.
The table result was 3NT-2. At the end, NS claimed they had been damaged by the explanation in the bidding and the play.
The double dummy analysis says that NS can make 9 tricks in hearts, and 7 in any other denomination.
Actual table results were a very mixed bag. 1NT* = W, 2S -3 E; 3S -1 E; 2NT -3 S; 4H = S; 2NT = N; 1NT +2 N.
I made a ruling at the time, but I would like to get some feedback on what should have been done. Thanks