I don't think the CBC was obligated to do anything. They chose to cut ties when it went public and therefore distanced themselves from the s-h-i-t-storm. I wouldn't call it an obligation.
You don't think people should be obligated to report a crime, that's fine but I don't know how it will benefit the CBC if they are aware of criminal acts and turn the other cheek. I think that would hurt the CBCs image more than just about anything else