Leaving base early

[Guest Umpire bill42]

Runner on first and third - one out.   Batter hits a long fly to deep left center.   Fielder catches it - -  the runner on first left early and does not attempt to return to first.  The left fielder throws the ball to first - first baseman steps on first to get the third out.      The runner on third tags up properly and vacated third on time  - and scores BEFORE the ball reaches first.   Does the run count.   I have had very experienced umpires come down on both sides..  Run counts/Run does not count..   

[Senor Azul]

No need to take our word for it or the word of any of your "very experienced" umpires—the answer to your question is in the rule book. OBR rule 5.08 Comment (the very last paragraph in rule 5.08(b).

APPROVED RULING: One out, Jones on third, Smith on first, and Brown flies out to right field. Two outs. Jones tags up and scores after the catch. Smith attempted to return to first but the right fielder’s throw beat him to the base. Three outs. But Jones scored before the throw to catch Smith reached first base, hence Jones’ run counts. It was not a force play.

[noumpere]

It's a time play; not a force paly.  The run counts

[ricka56]

It's Umpire 101 knowledge. The people who came down on the no run score side, are not as experienced as you think.  

[noumpere]

3 minutes ago, Guest Umpire bill42 said:

I have had very experienced umpires come down on both sides.

No, you haven't.    You've had experienced umpires tell you some version of, "It's a time play, not a force play.  The run counts."  You've had those with one year of experience multiple times tell you the run does not count

A runner can never be forced returning to a base.

A runner can never be forced once a trailing runner is out.

"tag the base" and "force play" are not synonyms.