Honestly, I can see both decisions.
I thought Pedro was running out of gas, but the Sox bullpen had been a problem all year long.
This was a classic case of "damned if you do, damned if you don't." Not sure why people don't just recognize that it was not an easy decision with no obvious right answer. Are we going on 17 years still second-guessing this? We have FOUR World Series titles, and if Grady made some move that worked out, the Sox potentially never hire Terry Francona. So maybe they not only lose in 2003 in the World Series to Florida, but also 2004 and 2007 never happen. And then who knows about 2013 and 2018, since so many other factors come into play.
Bottom line: Grady was screwed either way, and Red Sox fans have four massive reasons to be happy that things payed out the way they did...