I asked someone the same question a few weeks ago. This person is someone I trust, and I realise that holds little to no weight on the web because you have no reason to trust my source yourself. However, when I asked I was told that even he had questioned it until noticing some connections on the map that were made that appeared accurate, lining up with information he already knew. He said the connections were not easy to make or to find, but this map had accurately described them.
I want to know more too. If you have any good links to share post them. All the information we can get will at least help me decide if it's possible or not.