huh?

i simply don't understand why the issue whether bhutto died from a gunshot or from an explosion makes any difference. the guardian tries to explain:

Any evidence that a lone suicide bomber carried out the attack would support the government's assertion that al-Qaeda was responsible; proof that shots were fired would fuel the suspicion of many within Bhutto's Pakistan People's Party (PPP) that elements within the Pakistani state were to blame.

but that makes no sense at all. are they really saying that al qaeda doesn't have access to firearms? or that if the state wanted to kill her and blame it on al qaeda, it couldn't get explosives?