if snicko showed the ball hitting something else, or Haddin clicking his teeth or something, there'd be conclusive enough evidence for the third umpire to overturn the decision. But it didn't so the decision stood. Marginal decision at worst, not a stinker.
Nobody in the queue half as good as Pietersen, so he'll have to stay. Morgan, Bopara, Compton, all been tried and not quite up to it. There isn't even anyone in the queue half as good as Bopara. You could try out some beginners in the last test if the rubber's gone, but how did that work out with Woakes and Kerrigan last summer?