False, when the runner begins running back towards 2B, the force is reinstated.
who said he was running. the kids thinks it is a foul. he is going to be walking or at best a light jog which is far from a retreat(under duress). you have to take the whole play into account and use some judgement. the ball is already at the pitchers mound not coming in from the outfield.
ART. 3 . . . A force play is a play in which a runner (or two or three runners)
loses his right to the base he occupies and is forced to advance because the
batter becomes a batter-runner. For a given runner, a force play ends as soon as
he touches the next base or a following runner is put out at a previous base.
When a runner advances beyond a base to which he is forced without touching
it, the force play remains. Also, a force situation is reinstated when a runner
retreats past the base to which he was forced to advance.