DarkT1me, based on the comments about the map, it seems the author is just lazy, and the map is completed due to an unplanned coincidence that he wasn't even aware of.
Added 3 minutes later
wenwell, I bet that at best, he'll go underground and get hopelessly stuck there.
Considering that there are a couple of events and objects with errors on the map, I suspect that the author is indeed lazy, and that the map was completed by me on skeletons not "thanks to," but "in spite of" the author's intentions.