1: Everyone good will be united since they based their previous views on false pretenses.

2: No one is collectively guilty, since "not all are corrupt, (fewer than you think)". Almost no one knew the full picture therefore no one should be blamed for not knowing.

3: Everyone can question the evidence as much as they want, with no risk of being punished for it. After all, it's so much evidence, and every detail will be revealed.

I believe it will be mentioned later why this is relevant :)