If it went down as he reconstructed they made some bad assumptions about what a road really is out there. Not unlike that family that tried to take a shortcut through the mountains on a fire road and got caught in a snowstorm in Utah(?) a couple years back.
Part of the problem could have been whatever they had for maps. I have seen (in fact, I have) maps that show "roads" that I know are impassable for normal, passenger automobiles. The maps don't in any way warn about that. A good many years ago, when working at my first office job for a small company in New Haven, Connecticut, I was assigned to deliver some papers to the home of a client who lived in one of the New Haven suburbs. The boss looked up the address, pulled out a map, and gave me a route. Yes, the route led straight to the guy's house. What the map didn't show was that a five-mile stretch of the road on which the guy lived had been abandoned by the town years prior and was completely unmaintained. I actually made it through, but in the process I ripped off the brand-new exhaust system I had just installed on my pony car.
I found out after the fact that the road in question was a haven for local kids to test their off-road modified Jeeps.
I've encountered the same thing all across the country. Apparently technology hasn't helped. It's not uncommon to read stories about people who follow GPS instructions and drive right into lakes and rivers.
The author of the story alluded to a factor that many of you may not be old enough to remember: the "roadless wilderness" initiative of the Clinton administration. I ranted against it at the time, but for other reasons. During the Clinton days, the enviroweenies played a game of "creating" large tracts of national park and national forest land that were off limits to vehicular traffic because they were "roadless." The problem was, there were roads in there. Some of the roads had been there for a hundred to two hundred years. The administration solved that by simply printing new maps that didn't show the roads, but they were there. My problem with this was that the sudden cessation of road maintenance made for worse environmental damage than would have resulted from keeping the roads (and drainage) maintained. A side effect obviously was that if you had an old map that showed a road, the road could easily have become impassable due to lack of maintenance. That seems to have been part of the equation for the unfortunate Germans.