Game Situation: Baserunners Abandon Bases

 
One out with runners on first (R1) and second (R2). Apparently, only two at the game thought that there was one out (as the umpires soon learned)...
 
B1 grounds to the second baseman. Instead of starting double play, the second baseman throws to first for an easy force out of B1. R1 and R2 run half way to their next base, but then peel off and run into their 3rd base dugout. Simultaneously, the 1st baseman rolls the ball to the pitcher's mound and the entire defense runs into their 1st base dugout. After everyone is in their dugouts, the coach in the 3rd base dugout walks out and tells the plate umpire that there are only two outs. What happens next?
 
Is there a different action if there were no base runners during this episode?
 
Call
The runners are out as they abandoned their base running obligations. It is an umpire's judgment as to when that occurs (see NF 8-4-2p and casebook play 8-4-2C). I waited until the runners entered their dugout so there could be no question that they had abandoned their effort to advance.
 
With no base runners on, if both the teams believe that the half inning is over with only 2 outs, then I think the umpire has an obligation to remind both teams that traditionally 3 outs ends the half inning and they should return to complete the half inning. If they need a reference on the rule, feel free to quote the "Baseball Players Revised Rules of the Game, updated 1867" which states in section 29: "An inning must conclude at the time the third hand is put out".