Inb4 some weird edge-case where it can.
It's actually not super hard.
Player 1's hand: Tournament, Ambassador, Province, X, X
Player 2's hand: Smuggler, Moat, and several non-Province cards.
Player 1: Plays Tournament, reveals Province, gains Princess (and draws it), plays Ambassador (player 2 reveals Moat), selects Princess for the Ambassador's target, it gets returned to supply, but does not go to Player 2 because of the Moat. Turn ends.
Player 2: Plays Smugglers, gains Princess (a card that costs $6 or less).
Of course, this is bad play for Player 1. And sort of for Player 2, since he could've done the whole thing just by not Moating the Ambassador (but, then, he didn't know what Player 1 was going to choose).