Arizona had plenty of chances to win the game and they didn't. Honestly how do you let any receiver get behind you not once, but twice in an goal line situation in the corner of the end zone? (first one Holmes didn't grab onto) Just should not of been allowed to happen.
For what it is worth the refer did say "The booth said it was a fumble". Meaning some guy up there watched a quick replay and said it was a fumble and decided not to look at it again. Either way though that didn't lose them the game, what lost them the game was missed opportunities or blunders like letting the Steelers get behind you, in the end zone... not once, but twice in a red zone situation!