Bad Boys

This might be the best blooper ever. In this Bad Boys scene, you can very clearly see a camera operator in the shot. How nobody this is incredible. This accident has gone down in history as one of the best, though, so maybe it was a very smart mistake... 

Indiana Jones and the Last Crusade

Indiana Jones and the Last Crusade was released in 1989. The story itself was set in 1937, during WWII. One of the main conflicts in the film centered around the notorious book burning that went down during WWII. Indiana Jones was rushing to save his father's book from getting burnt. Unfortunately, the scriptwriters did not take into account when the book burnings happened. They took place in 1933, five years before the movie took place.