In the film "Citizen Kane", the entire plot revolves around a journalist attempting to find out the meaning of a billionaire's last words... "Rose Bud". However, at the beginning of the film - the event that sets the plot in motion - Kane collapses, drops the snow-globe he's holding, utters "Rose Bud" with his last breath, and then the nurse walks in to find him dead.
Considering that Kane was alone when the words were uttered, how does anyone know that he said them?