I'm having trouble picturing a scenario where you can thoroughly dominate an opponent but still have less than twice their score (unless they succeeded on a large Daily Double wager).
$19,000 to $3,000, double up on clues 59 and 60. I think that would qualify as a shellacking.
Even if it was $19,000 to $5,000 and the opponent doubles up, that's someone I would think about keeping around. If I'm stronger in every category than my opponent, how much incumbency on the buzzer is going to help him out? Plus I have the advantage that he knows he got thrashed in that game and survived only on my largesse and a right response in FJ. There's also the possibility that he'll offer the same thing back to me on the chance that the positions are reversed "tomorrow."
Much of Jeopardy is about assessment of risk tolerance and how to act on it, and I think this is a fascinating part of the game.