This is a hand from a Turkish Bridge club. All players are expert (of course ) Joke aside, they are all decent players.
South is thrown in against 4♥ and his side already took 3 tricks. They need an extra trick to defeat. South knows from the auction that West has Hxx ♠ but does not know which honor. So he tanks long time (confirmed by the players and kibs) and he decides to play J of ♠, covered by Q and North decides to duck immediately. West ends giving a ♠ trick for down one.
EW complains that the long pause by South gave his pd an UI, since no one would tank with JTx and his pd knew to duck the Q. North players say he would duck it anyway, because ducking would not have hurt even if his pd had JTx.
How would you rule and would your decision change due to scoring (IMP vs MP)?
Thanks!