All of you struggling with whether the force is reinstated because the runner may not have been intending to go back to 1B, comment on the part of the rule I have emphasized below (ASA)

My question is what did the umpire do?

Did the umpire call the runner out, thereby putting the runner in jeopardy because of a "bad call". If so, then I say the runner is put back on base and all other play stands.

If he called the runner safe then the runner had a brain fart, too bad runner out and no run scores.

Let me see if I have this straight. It sounds like there is a consensus that R2 made it to 2B about the same time as the throw that was dropped (OP called it a bang-bang play), and that he touched the base. Sounds like there is consensus that he is safe at 2B due to the dropped ball by F4. Not stated in the OP but we might expect him to have been called safe. Therefore at this point, the force is no longer in place. Is that right so far?

Now, the only way the force can be reinstated (at least in the sitch provided) is for R2 to retreat towards 1B. Is that right?

If I am correct so far, then is the crux of the matter whether heading to the dugout is considered "retreating towards 1B?" If so then the force it reinstated and if not, he is simply liable to be put out the same as if he were safe at 2B then wandered off the base in any direction (as long as he is on the playing field)?

Just giving you guys food for thought. Keeping us sharp before Nationals. ;)