Multiple teams-of-four, IMPs
1NT was 9-12
2♣ showed clubs and another suit
Double was not alerted. South thought it was for penalty, North thought it was Stayman.
Result: 2♣X(W)-4, NS+800
EW called the director at the end of play because of confusion over the meaning of the double. North was convinced their agreement was Stayman, but he couldn't prove it. South wasn't aware that penalty doubles of bids showing the suit should be alerted (give her another five years, perhaps). East said that had he been told it was penalties he would have bid 2♦.
How do you rule?