I've just watched the program and was rather disappointed they stretched their case too far. I've no problem with people trying to do this sort of thing, in fact I would have jumped at the chance to be involved with the building of such a "replica", but overall I felt they changed too much to really prove anything.
If I understood correctly...
No drawings exist of the machine they built for the program. They worked what it might have looked like from drawings of another plane with 4 wings. I wondered why they didn't build the plane with 4 wings that they have drawings for?
They filled in large triangular cut-outs in the trailing edge to increase the area.
They added wing warping and even then control looked marginal (perhaps due to lack of any yaw control?).
They added a seat to make the weight shift control work better.
They used a modern motor and fuel not a copy of his original. (Aside: Do drawings of his motor exist?).
All in all they did what Glenn Curtis tried to do to the Langley machine all those years ago.
Anyone want to build a replica of Penauds amphibian of 1876? Drawings exist (see below). It has elevators, a rudder, contra-rotating props and even retractable undercarriage
http://www.flyingmachines.org/pengau5.jpg