McDonald looks like he thought he was playing softball. I can't think of too many players who wouldn't have hit that pitch out.
So why did Valentine get to a point where he ran out of pitchers and had to forfeit the game?
Look at the innings after Buchholz: Miller 1.1, Padilla 1.0, 5 pitchers at 2 innings each. That's 7 pitchers to throw 13 innings, not counting the last inning to McDonald. Funny thing, the Orioles did about the same thing.
20 years ago, a mid-reliever goes at least 3-4 innings, so you don't need to carry 13 pitchers and run out of them in extra innings. Bullpens these days are grossly overused--mainly because pitchers have too many appearances and too few innings/appearance. As Johnny Sain said, half the wear and tear is in the bullpen heatup.