title: is it possible that SKPaymentTransactionStateFailed AND SKPaymentTransactionStatePurchased are 'called'?
body: <p>Is there a use case where first <code>paymentQueue:updatedTransactions:</code> is called with <code>SKPaymentTransactionStateFailed</code> and at a later time with <code>SKPaymentTransactionStatePurchased</code>?</p>
  
  <p>I thought I saw such a behavior when the user enters a wrong password (<code>Failed</code>) and then the correct one (<code>Purchased</code>), but it doesn't seem to be the case.</p>
  
  <p>I've got crashes with my app which I can only explain with the flow that first it fails and then succeeds. Does anyone know if that's a possible use case?</p>