Musharraf told reporters summoned to the presidential palace for a news conference on Thursday that it was Bhutto's decision to greet supporters through the sunroof of her armoured vehicle that was responsible for her killing.
Noting that those who remained inside were unharmed, he asked: "Who is to be blamed for her coming out of her vehicle?"
He said party officials should have stopped supporters from swarming her vehicle just before the attack, since any police action would have involved a baton charge or tear gas.
But Musharraf acknowledged problems with Pakistan's investigation and conceded that uncertainty remained over the exact cause of Bhutto's death last week.
Musharraf spoke as demands for an international investigation into the bombing and suicide attack that killed the two-time former prime minister intensified.
In an effort to blunt the criticism, he has invited Scotland Yard investigators to aid Pakistan's probe and conceded that investigators may have erred in giving a precise cause of death just a day after her December 27 killing.
"One should not give a statement that's 100 per cent final. That's the flaw that we suffer from," Musharraf said, noting that more evidence was emerging into the attack.
"We needed more experience, maybe more forensic and technical experience that our people don't have. Therefore, I thought Scotland Yard may be more helpful."
A team from Scotland Yard arrived in the country on Friday.
Musharraf also admitted there were shortcomings in Pakistan's handling of the case, including the hosing down of the bomb site hours after the attack, widely seen as undermining a detailed forensic examination.
But he dismissed any suggestion there was a plan to conceal evidence.
"I'm not fully satisfied. I will accept that. Cleaning the area, why did they do that? If you are meaning they did that by design, I would say no. It's just inefficiency, people thinking things have to be cleared, traffic has to go through," he said.
A senior police investigator, speaking on condition of anonymity, said that police had already secured key evidence from the scene, including the head of the suspected bomber, body parts, two pistols, and mobile phones.
Scotland Yard investigators, with their superior forensic techniques, could help determine whether either pistol was fired in the attack, he said.
Many supporters of Bhutto's Pakistan People's Party (PPP) have expressed doubt about the government's conclusion that she had been killed when a bomb blast slammed her head against her vehicle.
Bhutto supporters insist that a UN probe is the only way to reveal the truth about her killing, and reject a Pakistani investigation, even with British assistance.
"The regime has lost all credibility. Neither a domestic inquiry nor vague foreign involvement ... would lay to rest the lingering doubts and suspicions," Farhatullah Babar, a PPP spokesman, said.
The White House said it supported Scotland Yard's involvement, and that a UN investigation was not necessary now.
"Scotland Yard being in the lead in this investigation is appropriate and necessary and I don't see - we don't see a need for an investigation beyond that at this time," Dana Perino, the White House press secretary, said.