Well all the evidence points establishments deal with benazir got ruined after her demise.. Musharaf was to stay president while Benazir was to be PM. But suddenly a will came out of no where and zardari becomes the party chief. Next became the president himself and pushed the 18th ammendment to benefit his tribal friends which was something musharaf would have never done.
Establishment kept warning Benazir not to return at that moment because genuine threats at home existed but she didn't listen so who was giving her assurances that she will be safe needs to be understood.
It's an open secret Pakistans enemy in the neighborhood has taken advantage of a situation and got high profile murders done..