It seems that Zardari wanted power sharing with Musharraf and this would not have happened if Benazir was alive. So, in a secret truck with Musharraf, he got Benazir eliminated- both of them benefitted from this- Musharraf retains his power and Zardari becomes the head of the government (which he would never have been if Benazir was alive), and gets all corruption cases against him dismissed. In politics, especially when dominated by 'taqiya', anything can happen.
