ST. LOUIS — The Daniel Murphy Experiment continues to blow up in the Mets’ faces, at least on defense, as the young left fielder’s eighth-inning misplay Tuesday night led to a come-from-ahead, 5-4 loss to the Cardinals. Oliver Perez and Carlos Beltran didn’t help matters, either. In the notes, Beltran offers a pretty weak defense for why he didn’t slide while being thrown out at home on a pivotal play in the eighth.