What do the umpires do when a game ends on a scoring play, when an appeal (not video review) by the defense would succeed?
For example: bottom of the ninth, tie score, one out, runner on third. The batter hits a deep fly ball, caught by the right fielder. Runner on third tags up and scores the winning run. Game over. Everyone leaves the field.
But you're the third base umpire, and you know, without any doubt, that the runner on third left early, and, if the defensive team appeals, you need to be there to call the runner on third out with no run scored and the inning over.
On the other hand, to avoid giving hints to the defensive team, wouldn't you need to do the same thing (hang around third) if the runner had tagged up correctly? To avoid warning the defense in those cases where there is a successful appeal available?