Unless declarer is playing for a dummy reversal, he usually intends to ruff losers in the short trump hand anyway.
Alfred Sheinwold[1] cites this example of a forcing defense to South's contract of 4♠: NW ES West leads the ♥K.
He leads the ♠K, West ducks, and East's club discard discloses the bad trump break.
South has no better move than to continue spades, hoping for a defensive error, a winning diamond finesse, or that the hearts block.
At the end, West will make his small trump, winning in all two spades, a diamond and a club.