Batter-runner to 1B is a force play. You state that "By Rule" this is not a force. Please provide an OBR reference.

Jaska/Roder, Chapter 6, says "A. Any runner (including the batter-runner) is out when (2) he is forced out...It is a force out when a forced runner fails to touch (or pass) his advance base...before hts person or the base is tagged..."

The force is reinstated on the batter-runner at 1B if he retreats towards home. Refer to OBR 7.08(e) "...However, if the forced runner, after touching the next base, retreats for any reason towards the base he had last occupied, the force play is reinstated, and he can again be put out if the defense tags the base to which he is forced;"