BR Abandonment vs Force-outs

[dddunn3d]

Here's a play that happened last night during my son's game(league championship, which his team won 11-2, but I digress):

R1,R2, no outs. B1 hits a Texas-leaguer to shallow LF. F6 races back, stretches out, and gloves the ball but drops it as he falls to the ground. U3 calls "safe, no catch," but not very demonstrative. No IFF called because of the extraordinary effort to even get to the ball.

Runners hold thinking it was caught. (F6 is shielding the runner's view of the ball on the ground.) BR actually trots back to his dug-out(1B side) thinking he's out. F6 gets up, throws to F5, starting the triple play.

Here's my question:

If the BR entered the dug-out before the above action, being called out for abandonment, does that remove the forces at 2B and 3B? I believe it does.

However, here's the wrinkle in this sitch:

Is the removal of the force-outs considered a timing play? I.E., if the BR reaches his dug-out after R2 is forced at 3B, but before R1 is forced at 2B, does F4 now have to tag R1?