The winning run scored because Anaheim's second baseman, Macier Izturis, made an over-aggressive play. Men on first and second, one out, a grounder to Izturis's glove side. Instead of taking the sure out at first base, he tried for the tougher out at second, presumably in hopes of getting an inning-ending double play. He threw the ball past shortstop Erick Aybar, and Hairston scored (right).
Too aggressive. It was a dicey DP ball, and there was no reason to worry about a second runner in scoring position. Only Hairston mattered. Take the sure out, take your chances on the next hitter.
The Yankees thrive on other teams' over-aggressiveness. Torii Hunter in the first game of the series. Nick Punto and Carlos Gomez on the base paths in the division series.
You don't see the Yankees diving for balls on defense, and you don't see them taking chances running the bases. Earl Weaver would approve; he didn't want his players diving and running into walls. Such plays can result in injuries and misplays. Take the easy base, take the sure out, be in position, make the percentages work in your favor.
The Angels pride themselves on their aggressiveness. In the regular season, against bad teams, that can be effective. Bad teams miss cutoff men; bad teams throw to the wrong bases; bad teams can be pressured into making mistakes.
Flash and dash don't fare so well against good percentage baseball.