I'm just putting it out there because I know that everybody is thinking it but too afraid of the scorn that such an admission would bring.
What if the Balloon Boy hoax is a hoax? What if, to cover up the fact that they really thought that their fucking six year old kid might actually be soaring through the clouds in an aluminum foil bubble, the parents concoct the story that they concocted the story. They figure that the jail time or fines will be less for deceiving the media instead of reckless endangerment of a minor, so they proclaim that the whole thing was staged.
At least, that's what I would do.