Tag-up on thrown ball out of play?

Question
Situation: Championship coed softball, one out in final inning, we are the visiting team down one run, runners on first and second.
Event: Batter hits line-drive to 3B for an out, runner on 1B strays, third baseman throws ball towards 1B, but ball is overthrown and goes out of play.  Runner on 1B sees ball go out of play before getting back to 1B and continues over to 3B.
Umpire's Call:  Upon appeal from the other team, the umpire calls the runner on 1B OUT for NOT going back to touch 1B after the ball went out of play...Ballgame!
Question:  When a ball goes out of play from a throw, following a liner or fly-ball out, do runners have to go back and touch their original base before moving up 2 bags on the overthrow?

Answer
Hi Terence,

R2 would be out on appeal if they were off base when the catch was made and if they went to 3rd on the award and did not re-touch 1st after the catch, that is the correct call.

However in this case this is a dead ball appeal and cannot be made until the runner's complete their assignments and time has been called.  R1 on 2nd is awarded home and that run would count regardless of the 3rd out granted on appeal.  This is considered a timing play and is not a force out.  So by the facts stated in your question (unless I mis-understand the situation)the game should have been tied and you play the bottom of 7.

Mark