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:

• Islam is definitely a very anti-LGBTQ religion, so why don't liberals ever stage pro-LGBTQ demonstrations at mosques or at the consulates/embassies of Muslim countries?
• Could supermassive black holes anchor the tiniest galaxies? - Big Think
• What are some examples of a threat to democracy in India?
• Why does Rahul Gandhi have so many haters?
• Why after 50 years of being straight do I constantly desire to suck cock?
• Why do a bra and panties have to match?
• Why do some straight men like to suck dick but don't find other males attractive?
• What is a real life example of the Streisand Effect?
• Does the potential of making Star Wars R-rated movies depend on whether Star Wars have stories that is too dark for PG 13 in Disney?
• How do people who are deaf learn sign language? Is it typically taught by parents at a young age or are there programs available for learning it later in life?
• In what ways is Bollywood becoming westernized?
• Why is Nickelback known to be a bad band?
• What bait should you use for ocean fishing?