I was listening to the game on the radio a couple of days ago and I'm just now seeing this incredibly bad call. The umpire called Cameron Maybin out while the ball was still three feet away from the first basemen's mitt.
Broadcaster Bob Scanlan suggested that this is another reason why base runners shouldn't slide into first. The umpire can't hear the sound of the player stomping on the bag in relation to the sound of the ball hitting the mitt. It's a good thing the Padres eventually won the game on a bases loaded walk-off because this would have left a bad taste in the mouth. Like garlic fries bad.
Just a few days earlier Commisioner Bud Selig made this comment when asked about an increased role for Instant Replay:
"People in our sport don't want any more," Selig said in regards to expansion of replay. "Given our attendance and everything we're doing, we're in the right place with instant replay. Baseball is a game of pace. You have to be very sensitive and careful not to disturb that pace."
These "people" definitely don't want baseball games getting longer, but the commissioner's job is to make sure that the rules of baseball are being called properly. Which takes longer? Watching a manager argue and get tossed from a game or a simple look at some footage? This problem can be solved really easily by just giving a manager one challenge per game.