Neither lost, Palin did well because she exceeded low expectations, and Biden did well because he exceeded expectations by being anything but super windy and condescending.
Overall Palin ducked too many questions with a noun verb, I am a hockey Mom and me and McCain are mavericks. Biden, IMHO did far better on substance and probably won more uncommitted and independents.
Neither hit a home run, more like a walk for both than anything else.
But as the polls shift strongly to Obama and away from McCain, Palin did not have a strong enough performance to even stop the bleeding. And Biden did nothing to give Palin an iota of sympathy.
And so much for any Gwen Ifall bias.