"Indy, I love you!" --Short Round, immediately prior to torching Dr. Jones back onto the straight and narrow. Short Round Torch refers to any trigger--a friendly face, an impassioned plea, a musical strain, possibly a kick to the nads, or, as in the case of this trope's origin, a smoldering torch to the love-handle--that snaps a corrupted good guy back to his senses.
Hello, Unknown Troper. You'll need to get known to lend a hand here.