Can you give an example of a documentary where the person telling the story believed it to be true, but it turned out to be false?

Read also:

• Why did the massacre of al-Dawayima Palestinian residents not have the same reverberations as the Deir Yasin massacre?
• Do you agree with Pete Hegseth's comment that Obama created a moral divide between military and civilian life?
• Is it true that schizophrenia can sometimes be a demonic attack or black magic?
• How can a hacker damage me, realistically?
• What is the worst name in Tolkien’s legendarium (meaning and look)?
• Is Melania still angry that she failed as a model? Why is she so cold and hostile? Why did she blame everyone for her actions in her trite book?
• Why do women change that much more with age?
• How can the democrats say Mr. Trump is bad when he is already fixing this country again and he's not even president yet?
• Isn't it ironic people always talk about how much women hate Donald Trump, when almost any of them would marry him if they could? What he said in the 2005 Billy Bush video, almost every woman would share the sentiment if it got them his lifestyle.
• Is LGBTQ destroying the world?
• ‘Materialists’ Production Designer and Set Decorator Estimate How Much Rent Each Character Pays for Their NYC Apartment - Variety