A hot dispute

I was having lunch in the club lounge when two players brought me today’s deal and asked me to settle a hot dispute. “When my partner opened three clubs,” the player who had been North told me, “I bid 3NT — and I would do it again. If the opening leader leads a red suit, I have 10 tricks. It was unlucky that my partner was void in spades, the opening lead was a spade and they ran five spade tricks.” “Your 3NT was horrible,” South insisted. “You could raise to five clubs.” “With a spade void, you should pull 3NT to four clubs,” North retorted. “Then I might raise.” “Five clubs goes down,” South countered. “With strength in the side suits, West would surely lead a trump. He would lead trumps twice more when he won heart tricks, and my fourth heart would be a loser.” What think ye? Would you fault North, South, neither player or both? I can sympathize with North’s 3NT bid, though it led to a result that looked silly. From his point of view, the nine-trick game looked likely to succeed. The 11-trick club game was speculative. South’s pass to 3NT was automatic. For all South knew, North held A 5 3, A 5 2, K 10 7 6, K 4 2. South was wrong that a trump opening lead would beat five clubs. With good timing, declarer can win 11 tricks with a dummy reversal. He wins the first trump in dummy, ruffs a spade, leads a trump to dummy, ruffs a spade, takes the ace of diamonds, ruffs a spade, goes to the king of diamonds and ruffs a diamond. He returns to the ace of hearts and ruffs the last spade for his 10th trick, and dummy still has a high trump.