Oooh, an edge case topic.
If we're talking about edgiest of edge cases, the following will suffice:
It's heavy greening time. You know your next 5 cards will be 4 valuable VP cards and Bank.
You're playing Bureaucrat, gaining a Silver on your deck, (making you draw it next turn instead of a VP card) and looking at the opponent's hand, he has no VP cards. You've played some Rabbles and the next 2 cards on the opponent's deck are 2 Provinces.
Your opponent's cards are Masquerade-Governor-Necropolis-Copper-Copper.
If you pass him the Silver, you're hoping that he will use Governor to turn it into a Duchy, letting you remodel Bank into the last Province to take the win.
Why doesn't he just use Governor on the Masquerade? Well, obviously he's hoping you'll pass him something nice for his Copper and with an action to spare you can't just pass him any action card.