Unless this was rigged, this is an inaccurate depiction of the event.
There is a difference between the Pledge and the Anthem.
If the Pledge of Allegiance had ended, why did Hillary and Richardson and the other person present on the stage still have their hand(s) prominently over their heart(s) while Obama had his hands casually clutched together in front of himself?
Obama has said, in response to the criticism, that he does place his hand over his heart while stating the Pledge in the Senate Chamber. That obviously leaves a lot unsaid about other times and places.