(Based On Hand From EBL Workshop)
After South’s weak no-trump opening, North bids Stayman, South shows his spade suit, and South declares in 3NT. At this stage, East leads his ♠Q out-of-turn.
The Director now explains all the usual options to South, and South enquires as to the opposition’s lead style, and is advised that the lead of a Queen shows either QJ10xx, or KQxx (he can’t lead the K since this is the unblock card). After some thought, South says that he doesn’t mind what West leads. The Director clarifies that West can lead whatever he likes, the ♠Q now remains on the table as a penalty card, and there is no UI to West (Law 50E1 – Information derived from a penalty card and the requirements for playing that penalty card are authorized for all players for as long as the penalty card remains on the table).
West now leads his ♠2, East per-force plays his ♠Q. South, unsure as to whether East has four or five spades, and assuming East will continue a spade, decides to duck. East now switches to ♦9, and following declarer’s unsuccesful finesse, West continues a spade. Declarer now loses three spades, a diamond, and a club – one off.