Wow, many questions and threads about the movement in Whistle Stop. I hope I get it right. Anyhow: an question:
Are you - with a whistle - allowed to move to a neighboring stop and return to where you originally started? After reading these rules, my gut feeling says no however you may return on the same tile as a result of a followed path without backtracking.
A whistle doesn't let you move A>B B>A, where the 2nd stage mirrors the 1st stage.
However, you are allowed to return to your starting point if you can accomplish this without retracing your steps, e.g via a loop.
So, I believe that your gut feeling is correct.