With passed balls it is a nobrainer, Fielder all the way.
Orginal question: I think a freak inside the parker for Colon is more likely than a active steal of home for Fielder. I thought he might evade a rundown and be safe at home, but by this video, the only rundown Fielder would evade was one executed by the weight watchers.
https://www.youtube.com/watch?v=0jvNLOwUeQE
Then again, it needs to be a real one in a million play to let colon circle the bases - look at him compressing what would be a hr for any speedy guy, a triple for a hustling colon, into a double:
Colon's RBI double | MLB.com