Flyman (and Owl)--I wholeheartedly agree with Flyman--unmitigated crap and unrealistic in many ways, with an invitation to giardia being right at the top of the list. As for foodstuffs, how can you even think about starving, if you are reasonably skilled in woodscraft, in the most ecologically diverse area in the northern hemisphere? There are hundreds of edible plants, not to mention considerable fauna, in the Smokies.
Owl, the "bear corn" is much more commonly known as squaw root. It is incredibly abundant (my Grandpa Joe would have said "common as pig tracks"), and anyone who has done much turkey hunting in the southern Appalachians has seen plenty of it. The name comes from the fact that Cherokees considered it useful for various women's diseases and for use following childbirth. Bears do indeed love it, but in the season when it is at its prime I'll personally take a mess of ramps and branch lettuce, with morels on the side.
Standard wisdom may suggest staying put when lost, but in the Smokies I don't totally agree if you have decent skills in the woods. Obviously it is foolish to travel at night unless you have a good source of light, but in the daytime there are two logical approaches to take if you are lost or, as Daniel Boone once put it, "temporarily misplaced." Try to get to a ridge line or follow drainages. In general the latter is preferable, because more trails follow streams than they do ridgelines, although both are common enough. That wouldn't be for everyone, but for someone conversant with the land and with a moderate degree of fitness, it would be preferable to have the NPS spend untold man hours and expense to correct your screw-up.
One other thought, and I'll offer it despite the fact that I harbor a world of negatives about Horace Kephart and will be offering a son of the Smokies' view of him from something of that perspective in an event at UT in early November. Forget the literary abomination which is much of Our Southern Highlanders
(when one scholar described it as the "Nadir of Appalachian stereotyping" he was dead on). Old Kep flat-out knew his woodsmanship and truly deserved the moniker "Dean of American Campers." Other than changes in technology, his massive work, Camping and Wodcraft,
remains quite valuable and accurate even today, and some testament to its value is provided by the fact that it has never, since original publication, been out of print.
As for the show, I know any number of fine mountain folks who teach that pair not one but a whole passel of lessons in dealing with the land.