"You will give the order to remove Dolores Umbridge from Hogwarts," said Dumbledore. "You will tell your Aurors to stop searching for my Care of Magical Creatures teacher so that he can return to work. I will give you ..." Dumbledore pulled a watch with twelve hands from his pocket and glanced at it "... half an hour of my time tonight, in which I think we shall be more than able to cover the important points of what has happened here. After that, I shall need to return to my school."
The Order of the Phoenix Chapter 36: The Only One He Ever Feared
Como parte dos pontos importantes do que aconteceu, Dumbledore certamente teria mencionado que Sirius morreu e, através de sua infinita credibilidade na época, provavelmente teria convencido todos da inocência de Sirius.
É bastante difícil negar a palavra de Dumbledore momentos após ele ter lutado contra Voldemort.