OBS is not called for blocking the plate or being in the base path without the ball. OBS is not called because a runner slows down. OBS is called for impeding the progress of the runner without possession of the ball.
Did the fielder impede the runner?
Not did the runner slow down, but in essense, was the fielder the cause of the runner slowing down?
Other reasons the runner might slow down:
- giving up
- indecisive, or even
- trying to draw a OBS call since she is a dead duck
In the original scenario, as described, F2 did not impede, therefore no OBS.