Dont think they choked as such, cause they played well, but just failed to raise their game when it mattered most. I would say that they got a number of their strategies wrong as well, Im not sure why they didnt have one of Morkel, Van Der Merwe or Boucher bat up the order.
Whether you like Pakistan or you hate them, they were smart in having someone like Afridi bat 3 to play the pinch hitter role early, not to mention Akmal having the lincense to do whatever he wants because they still have the more sensible and reliable players like Younis, Malik and Misbah to come in the middle order. SA missed a trick with Smith, Kallis, Gibbs, ABD and Duminy all coming in one after the other, especially with the 2 most aggressive out of them failing to fire today.