This whole thing happened in the sixth inning of today's Phillies/Marlins game. Hunter Pence of the Phillies hit one to the right-field wall. It may or may not have hit that yellow stripe. We'll never know.
Before Bryan Petersen of the Marlins could catch or miss it, his glove hit a spectator's hand and the ball hit either that spectator's hand or the ball cap that another fan held out to try and grab it. That fan was in a Phillies jersey, of course. The umps ended up reviewing the play, which apparently — read: the homer TV announcer's explanation — is something that only occurs when a possible home run is in question. Which there apparently wasn't.
So, the go-ahead run was rescinded, Phillies manager Charlie Manuel got ejected and the game is being played under protest. That's a rarity to the point that the Phillies booth keeps talking about George Brett's pine-tar situation, which is another notable instance of games continuing despite a formal shenanigans declaration.