If that was the case there would never be a movie based on an unofficial biography or real life true crime story made into a movie that didn't claim to be a documentary. You remember ARGO, the film that got Ben Affleck an Oscar (or Oscars)? Ask him why there are restaurants in Canada that won't take his reservations anymore and why the original author of the book it is based on supposedly won't take his calls anymore. What about every movie about serial killers? What about stories about unsolved murders that were all research and no one giving them permission.

Just like you have the ability to film in public because in a public place, with some exceptions, you do not have an expectation of privacy, once something reaches a certain point of public noteriaty you don't need anyones permission to make a film based on it.