Northern Ireland
MPs scoring. South was in 1NT on the board above (pips approximate). At trick 9, East couldn't lose a trick if she tried, but elected to play it out and on trick 10, leads the ace of spades to which West discards a diamond and then follows suit again on trick 11. The result (before adjustment) was 1NT-1. How do you rule? If it matters, E/W are beginners and N/S are fairly experienced.