This gets complicated at public events where something goes wrong and the reported story is not consistent with the facts. Bystanders can witness the event with

This gets complicated at public events where something goes wrong and the reported story is not consistent with the facts. Bystanders can witness the event with their own eyes and then go home to watch the news, to then believe the news-worthy version of the event. A spiral of silence sets in so all observers of the original event fall under the same spell and assume they are wrong and adjust their view to the world view rather than what they saw with their own eyes. At public events you also get a completely different view of what happened depending on whom you ask. Not everyone gets the complete story or picks up on all the clues. People bring their own expectations of what they expect to see and have cognitive dissonance to make it so they do see what they see and not necessarily what happened. The JFK incident was in this realm of unreliable eyewitness memory, those that thought they saw and heard the second shooter changed their view over time to align with the accepted story. This is how it works.