I'll get you up to speed, so you can just skip all the official review in between: First inning, bases loaded in Busch Stadium for Michael Morse. He hits a long fly ball which bounces off the top of the outfield wall, hits the Energizer ad behind the wall, and comes back into the outfield. The ball is in play, and after the subsequent relay, Morse is tagged out after a shambling rundown between first and second. But: the back wall at Busch stadium is actually out of play, and after some standing around, the umpires establish that fact. Second but: Morse must go back to the batter's box and go through the motions of hitting a grand slam—with a swing and without a bat, in Morse's interpretation—for the runs to count, because baseball makes you touch every base, even when it's obvious what would have happened.
We join the action at around 2:50, as the umpires announce that it was indeed a grand slam, and Morse is rounding second for some reason:
h/t David L.