I agree with you to a point, but the quote you reference in your post #8 of the uncle saying "It's a beautiful story" makes all the difference to me, in this case. That one inadvertent comment told me from the gitgo that there was a hidden side to this whole thing, and the Smarts knew more than they ever revealed. Probably even to the cops.
No screenwriter is ever going to explore that dark area in the telling of the story. It'll simply be TV fodder as a story of a family's struggle, with a happy ending. I think only the Smarts know the true plotline here, and they obviously ain't tellin'. That's the story I want to hear.
Illbay pointed out that the comment from the Uncle was bogus. I don't have any credible links to whether Tom did or did not say that. I'll concede this one to Illbay unless someone has a link?