I disagree that he had a split second to stop his action. It is worth noting that all the other players manage to stop when the whistle was blown including Prestia and the swans player who infringed who were both closer to the ball. This is before the Swans player grabs the ball off the ground then kicking it in the stands.
This also demonstrates that all the other players heard the whistle. Though, I still believe that the swans player who kicked it didn't hear it (I don't think he would have done the actions if he did hear it, just all other players who infringed in the past), It does demonstrate that the circumstance isn't all that different when players played on in the past when a 50 is paid against them but didn't hear it and it wasn't accepted as an excuse.
What? None of the players stopped before Warner. Watch the video.