I am sure Monk will have something more erudite to contribute but I seem to sense a the lack of a killer instinct in Torre last night.
In a nutshell, Francona uses Papelbon down 4-3 at home in the 9th. Papi hits a two run bomb in the bottom of the 9th to steal a win for Boston.
TIED 1-1 away Torre uses Chris Britton. Britton gave up two singles with a stolen base in between that cost the game.
Sure Vizcaino had already been used, Joba had pitched the night before and so had Mo. Putting myself in Torre's shoes he's thinking "I've won seven in a row. I can't use Joba and want to save Mo for Boston."
That's bad thinking because a win is a win and even though a 5 game lead (at the time) in the loss column over Detroit is good with 19 or so left to play I would have tried Mo for at least an inning, counting his pitches. At the end of the day Boston hits Mo better than most and a win in Toronto is probably easier than a win in Boston under similar circumstances.