IMP pairs, played behind screens. Qualifying phase of Switzerland's national pairs. The double was not alerted on either side of the screen. Before his final pass, North asked East about the double. According to East, she said either "spades" or "pique" in response. According to North, East gave a little shrug and said penalty. West lead a spade and E/W cashed the first six tricks.
After the hand, North asked again and was told that the double asks for a spade lead and "everyone plays it that way." He called the director, claiming that he would've removed to 5♣ if he had known the meaning of double.
How do you rule in this sort of situation? If it makes a difference:
1. Paper and pencil were available, but many people were not making use of it in the event.
2. The rule on alerting the double is that without screens no double is ever alertable. Behind screens such doubles are supposed to be alerted (but it is likely E/W did not know this).
3. All players at the table are supposed to be strong/experienced players, although the standard in Switzerland is lower than in some other countries.