People are going to throw a fit about this one in the comments, but here we go:
In Django Unchained, people claim and share the wild story that Leonardo DiCaprio smears his own blood all over Kerry Washington's face because they were so in the moment of the scene.
This one is a classic example of trying to make a real movie fun fact even more extreme. Yes, DiCaprio sliced his hand on a glass. BUT, the blood he wipes on Kerry Washington's face was done with fake blood they poured on DiCaprio's hand between takes after wrapping the wound up. There are clearly cuts within the scene and disproportionate amounts of blood on DiCaprio's hand from shot to shot. Just because people, and even actors, try to pump up a behind-the-scenes moment, doesn't make it true (see, again: Judy Garland claiming the munchkin actors had orgies).
I'll say this, if I were DiCaprio, I would come out and confirm this, because otherwise, he rubbed his own blood on his Black co-star's face while in character as a slave owner. I certainly wouldn't want that for my public image.