Conspiracy theories are immune to evidence. They are inherently self-sealing. Evidence that disproves a conspiracy theory is reinterpreted as originating from the conspiracy.
When faced with evidence that disproves flat Earth, rather than considering the evidence, flat-Earthers will simply invent an “explanation” that the evidence was fabricated by those in the conspiracy & include those who told them the evidence as being part of the conspiracy. Sometimes even evidence that can be personally verified also gets the same treatment.