Les Stroud does extensive research. I'm sure there is a link, but he's mentioned a few times in Survivorman that he uses local guides to get a lay of the land, especially for plant life. Every place is unique, and he needs someone to tell him what is good and what is lethal. If I recall, in his shows, you'll hear stuff like "XYZ plant is plentiful in this region, it provides...can be cooked/eaten raw...". I believe he also has a pretty good idea of which way is out. The point is to show surviving for 7 days, not necessarily what to do if you get lost!

But, since Les is his own boss, he doesn't need to follow OSHA regulations ( well, maybe he does, but he'll be the only one dying. Can you imagine the backlash if OSHA goes after him for something he does during his show? The EPA on the other hand.... )