wouldnt an autospy be a crucial part of an investigation and help find the lead to the assassin by matching the bullet to a gun? an autopsy is mandatory under pakistan's criminal law in this type of case anyway. but if you want to be disinterested in the truth and blindly believe that al-qaeda evil doers did it without any shred of evidence, then be my guest.
I do believe the assassin blew himself up right in front of everyone. Not a whole lot of mystery there.
Not to mention to match a bullet to a gun you first need a gun and a link as to how it would be there since many guns use the same type of ammo.