The two real lessons here:
1 - Never go to the press thinking you can use them as free advertising. 60 Minutes' smear piece was predictable for just the reason cited in the film - that they had to change the story to make it theirs and keep it vital. Whether the kid really did the paintings or not, 60 Minutes would have made the same piece.
2 - People generally are WAY to ready to believe they know what's going on based on one source. The hate mail following the 60 Minutes coverage is proof. Once again, forget whether the kid did the paintings alone or not. Regardless, the people who's only source of information on the subject was a 60 Minutes segment had no real idea what the truth is. This didn't stop them talking about damning the parents to hell etc.
As the original journalist says near the end, this really is a story about what happens to stories, and it says a lot more about the adults reacting to it all than it does about the kid or her family.
"I'll book you. I'll book you on something. I'll find something in the book to book you on."