To answer that question calls for a journey through the history and
sociology of science, a journey so long that it calls for a book or books.
But it is clear that stations along the way will include the following:
Far from everyone has been wrong: many competent, indeed distinguished people with relevant credentials have persistently denied that HIV has been proven to be the cause of AIDS. Convenient introductions to the considerable volume of dissenting opinion are the web-sites healtoronto.com and www.rethinkaids.info, the latter being maintained by the Group for the Scientific Reappraisal of the HIV-AIDS Hypothesis.
which either singly or collectively demonstrate that fact,
at least with a high probability.
There is no such document.
That comes from Kary Mullis, who received the 1993 Nobel Prize
for inventing the polymerase chain reaction (PCR), which is used
universally in DNA studies.
An ironic twist: that HIV is not the cause of AIDS is hinted at in the autobiographies of the two people credited with discovering HIV, Robert Gallo and Luc Montagnier-- see review of those books
Perhaps the salient point is that the popular mass media have ignored dissident voices. Those who dissent from the mainstream view are in limbo--excluded from funding, excluded from mainstream journals, treated as cranks by the mass media. There has been an almost complete lack of investigative science reporting about HIV/AIDS.
A central point is that “science” is hardly at all nowadays a search for truth by curious and dedicated individuals. Primarily it is a highly organized and thereby bureaucratic activity. Those who speak for science are typically bureaucrats, not people actually doing science. Too much science nowadays is a matter of knowledge monopolies and research cartels (Journal of Scientific Exploration 18 (2004) 643-660)
Those who do the actual science are mostly “cogs in the machine” who do not spend time thinking about the broad picture. Those who accumulate and organize and publish periodic official reports do not ask themselves whether the data fit the prevailing theory, that is not their job. So it has happened that the accumulated data clearly shows that the standard theory is wrong, without that having been noticed--apparently--by the people who prepared the reports. As a matter of fact, one can find in various individual reports, statements that the data are puzzling; yet the conclusion is never drawn that this is because the theory is wrong.