My roommmate still believes FIP is a made up, useless stat and that pitchers should just "throw better pitches" and ERA does everything FIP can do. Today, in the first inning, Espinosa missed a play on the first batter (leading to a runner on 1st) and then completely misplayed a routine double play ball, but still managed to get the out at first. On neither play did he receive an error, though Zimmermann's defense clearly cost him baserunners and then, a run. Zimmerman was charged an ER for that play, so his ERA wasn't good, but if not for poor defense, he gets no runs against. Then, Zimmerman's decision to throw to Espinosa instead of getting an out at 1st also was not an error, so it's still an earned run even though the pitcher got a routine ground ball that went haywire because a fielder made a bad decision.
There's no more textbook case for why FIP can be a nice measuring tool, but since they weren't errors, he doesn't think the pitcher should be somewhat vindicated (only in the sense that he may have pitched better than his final line).