Here is what happened last night. 2 outs runner on 2nd. Batter hits grounder to 2nd. Bad throw to 1st leaves the 1st baseman sitting on the base bobbling the ball between his legs. He picks it up and the ump calls out. But drops it too soon and ump says safe. There was enough delay in the out to safe change that the infield players had started to the dugout. In the meantime the guy from second has went home. Ump sticks to his safe call and allows run to score. Guess I always thought a ump can't change his call. And if he can should the play be dead or is the run allowed to score even though everyone quit the play as soon as he said out since it was the 3rd out?