A good story, but 30' of rope seems a bit excessive.  I believe the normal length was 6'.  There have been several stories like this one, but the only one I can think of off the top of my head is the movie Jacob's Ladder (unless I'm not remembering the movie correctly).  I agree that it's not necessarily easy to figure out what's going on at first, but when he starts feeling pressure on his neck, it may be more obvious then.