The 55-year-old concert promoter - a friend of the late 'Thriller' singer since he was 11 - insists the pressure of preparing for a 50-night run of concerts caused the fatal suspected cardiac arrest that killed Michael on Thursday (26.06.09), singling doctor Tohme R. Tohme for particular responsibility.
David said: "We all have weaknesses and Michael's was that he trusted the wrong people most of the time. He thought people were good, which they are not.
"Michael was in terrible pain and all he cared about was feeling better. He started taking prescription pills to numb the pain and he also started drinking. It was then that his judgement started to become clouded.
"Michael told me he was excited about getting back on stage. But I really believe in my heart of hearts that the pressure of those concerts killed Michael."
David believes his friend was misled when he agreed to his 'This Is It' residency, which was due to begin at London's O2 arena next month and the stress of such a gruelling schedule was "too tough".
He added to Britain's The Sun newspaper: "Michael thought there was going to be 10 dates as announced. But then all of a sudden Thome, with Randy Phillips, president of organisers AEG, had arranged 20, then 30, then 50 dates.
"Michael was being told, 'You are going to set the world record for concerts at the O2.'
"They knew how to feed into his ego. But when Michael realised his schedule he began to panic. They should have realised doing one concert a day, then one day off, would be tough for any performer, let alone someone who hadn't been on stage for nine years, it was ridiculous.
"Michael was working his a*s off for eight hours a day to prepare, the schedule didn't allow him any time to rest. I know for a fact he was rehearsing until 2am the morning before he died."
Meanwhile, singer John Mayer says the 'Billie Jean' star - whose career faltered following a string of child sex abuse allegations - has returned to "pristine condition" in death.
The 'Gravity' hitmaker insists his hero's passing means that fans can fully appreciate his music again without it being tainted by scandal.
He said: "We don't have to reconcile the Michael Jackson we love with another Michael Jackson. In a way, he has returned to pristine condition in death. We can be free now for the rest of our lives to love the Michael Jackson we used to love."
John also praised Michael's musical talent, saying his work was to such a high standard it embarrassed other musicians.
He added to Time magazine: "He was one of the purest substances ever in music. But it's frustrating, and somewhat pointless, to ever try and figure out how Michael Jackson arrived at an album like 'Thriller' and how you could arrive at something like it.
"It's one of those things you actually don't want to bring up to musicians because they don't want to remember that that kind of greatness is achievable, because it skews the entire bell curve completely."