Sometimes you just have to believe your own eyes

The California Angels have just defeated the New York Yankees 5-4 in 11 innings following some bizarre managing by Yankee skipper Joe Girardi.
In the bottom of the 11th, the Yankee relief pitcher, David Robertson, set down the first two Angels he faced. The second of the two was Kendry Morales, a star slugger. Robertson retired Morales on a lazy fly ball after delivering pitch after pitch at his knees and either an inch or two outside or an inch or two inside the strike zone. His command seemed total.
But then Girardi pulled Robertson and brought in Alfredo Aceves to pitch to Howie Kendrick. Aceves, a right-hander like Robertson, has been unimpressive in this post-season. For the season his numbers are comparable to Robertson’s though he’s been a little tougher on right-handed hitters (Kendrick is right-handed).
Kendrick promptly singled up the middle. Then, after falling behind light-hitting catcher Jeff Mathis (another right-hander), he grooved a mediocre fastball. Mathis drilled the pitch for a game winning double.
What would possess a manager to take out a perfectly competent reliever with good command on the day, after he had duly retired the only two hitters he faced and where he has the “platoon” advantage (righty vs. righty)? Perhaps Girardi had some statistically-based rationale. Conceivably, the numbers in question were statistically significant. But sometimes don’t you just to have to believe your own eyes?
UPDATE: I really should leave the second-guessing of Girardi there. He knows his club, and managed it to the best record in baseball; I don’t. I’m struck, though, by the way he’s run through his bullpen in the past two games. Another argument for sticking with Robertson was the fact that the Yankees only had two pitchers left [note: relief pitchers, that is, according to the announcers] in a game that could have gone on for half a dozen or more innings.
The reason the Yankees were down to their last two pitchers with two out in the 11th is that Girardi uses his pitchers for such short stints. For example, after left-hander Damaso Marte retired the one batter he faced in the seventh inning, Girardi pulled him and brought on another lefty, Phil Coke, to start the eighth. Coke faced one batter and was replaced by a right-hander to face a right-handed hitter. I understand the second of these moves and for all I know the first might made sense at some level, as well. However, after watching two games of this, I can’t help but suspect over-managing.