I see a few options for how to finally rule this:
Option 1)
-- The fellowship is "at" whichever site the site marker is on.
Pros: Simplest to explain; explains why "moves to..." text on the new site is active; the site marker and the
site the fellowship is "at" is always the same
Cons: Because of the 2002 CRD ruling for
Bill The Pony, this would either require the 2002 CRD ruling to be
"overruled", or a clarification added to
Bill The Pony (as MarcinS suggested).
Option 2a)
-- The fellowship is "at" the previous site until all the twilight is added, then the fellowship is "at" the new site.
Pros: Seems consistent with the existing rulings; matches the 2002 CRD ruling for
Bill The Pony Cons: Not very straightforward since the site marker and the site the fellowship is "at" is not always the same;
would require a clarification to explain why "moves to..." text on the new site is active.
Option 2b)
-- The fellowship is only "at" the previous site until the fellowship starts moving, and the fellowship is only "at"
the new site after all the twilight is added.
Pros: Matches the 2002 CRD ruling for
Bill The Pony; the site marker and the site the fellowship is "at" is always
the same.
Cons: Would require a clarification to explain why "moves from..." and "moves to..." text on the sites is active;
would require a clarification to explain why The Balrog is not discarded while the fellowship is moving
between underground sites.
Keep in mind that the rules for this game were written by human beings, who do not always think of every situation, and many times needed to clarify a rule or card after the fact. Therefore, we still sometimes find rules that conflict with each other.
Let's decide how to resolve this situation. After we do, I'll update the "Unofficial Rules Document" that I maintain, and life goes on...