Who's to blame for the bias?

Watching excerpts of interviews with Robert Zimmerman and Robert Zimmerman, Jr. as they defend George, I am taken aback by their obvious lack of a proper term. In all that I seen, both of them are saying what happened to George: He was on the ground, he had to move his head to ensure he wasn't beaten up worse, things like that. But were they there? No, and so they never should state what happened, but that George had said that these things happened. If they aren't saying it, they're biasing one side of the discussion, and stations should point this out. But if they said that, and certain stations are refusing to air that part, they are trying to bias the other side of the discussion. And if the stations are trying to bias viewers, that's much worse and much more troublesome than the family defending George.