Lucien, I DID research your PBS show, 'How Criminals Get Guns'. It was about straw purchases and illegal street sales. Since you claim it was about gun shows, here is the link -
www.pbs.org/wgbh/pages/frontline/shows/guns/procon/guns.html
(You may have to copy and paste as I do not know how UglyHedgehog handles links.)

There was also a hit piece at an alleged Tucson Gun Show that had one gun purchase from a supposed private seller with all of the rest of the video concerning purchases of magazines and accessories, not firearms, at this link-
www.gunshowundercover.org

There is no way to verify where or when this video was made other than the claim by the narrator. To paraphrase your question - Are you really that gullible?

Lucian, I have attended numerous gun shows and have yet to find one where NICS checks are not required. The vendors who do not use them sell jewelry, holsters, books, range bags, knives, and other items of interest to collectors. Oh, a few sell food. For a former LEO and gun enthusiast you sure lack accurate knowledge.