So your strategy was basically "Wishing Wells, Cellars, and Hunting Parties to draw into lots of Copper + Coppersmith," right?
I think that you basically got lucky. Your opponent really shouldn't have bought a King's Court, in particular: a Gold or Harem would have been much better for him (unsurprisingly, given that his deck at end of game had 4 potential targets for the KC, compared to 15 Treasures and 8 pure green cards), and the score was close, meaning that a small improvement from your opponent would probably have won it.