Situation is bases loaded, one out, 5th run on third. Batter hits short fly ball to right center. Fielder catches the ball and throws toward home but runner beats throw. However, the runner on first led off before the catch and never returned to first base. Throw goes to first which is the third out and is a force play, no tag needed. Inning over and the fifth run should not count as the play continued. Or so we thought.

Both teams have former umpires. One says the fifth run should not count and the other says it should because force plays only happen going forward, not going back to the base.

Comments....

Brock based on your scenario the runner on first is not required to go to second so this is NOT a force play. It’s a timing play. It sounds like the runner at third crossed the scoring line (or touched the scoring plate) before the runner on first was doubled off. Run scores.
If the runner on first was doubled off before the runner at third scored then the run does not score.