Speed Of Lightning Play

Another hand from the Junior Invitational in Beijing. I have often wondered whether I was lucky or good on this hand - not that there is anything wrong with that. I received a diamond lead and, through some rather specious reasoning, decided I would prefer to lose a trick to East. I won the A♦ and led the T♣ from hand. This hit the jackpot when West ducked from ♣Qxx.

I am currently dipping in and out of 'The Rodwell Files'.In the section 'Speed Of Lightning Play', I came across the hand below. East was Fredin from Sweden. When he received the T♥ lead, he reasoned that South probably had awkward holdings in the minors. After the Q♥ won, he came to hand with a diamond and led a low club. South ducked and the hand is routine from there. This is a Speed Of Lightning Play, taking advantage of positions where defenders play low quickly to avoid giving away their holdings in a suit.

After seeing the latter hand, I think maybe I made the correct play on the former hand - albeit for the wrong reasons. Do you think I was lucky or good?