http://mlb.mlb.com/video/play.jsp?content_id=15023115
He didn't pass him. Unless there's something I'm missing, it was a horrible call.
According to MLB's play-by-play: Ryan Ludwick singles on a fly ball to center fielder Franklin Gutierrez. Chris Denorfia scores. Jason Bartlett to 2nd. Ryan Ludwick out at 1st, first baseman Justin Smoak.
According to Yahoo!: The Padres avoided their ninth shutout when Peguero couldn’t hang on to Ludwick’s fly ball as he tried to make a diving catch. Ludwick’s single scored Chris Denorfia(notes), but Ludwick was called out for passing Jason Bartlett(notes), who had turned back to first base, thinking Peguero had made the catch.