East had been under pressure, and thrown two cards from each minor suit.

On the next two diamond winners East threw a heart and a club.

East threw the spade queen, and West was in trouble.

East had thrown a club, so Rosenberg led that suit.

West led another diamond, which forced East to throw a club.

But on the third club East threw a diamond and discovered the error too late.

East had thrown a club at the first trick and now, under pressure, gave up a heart.

South ruffed and led a club, on which East threw a heart.

If East had thrown a heart, South would have led that suit.

The effect is the same if East throws a heart at the first trick.