Runner on 2nd, no outs. The batter smashes a hard grounder that skips by the charging shortstop and hits the base umpire, causing the ball to bounce to the second baseman who throws to first in time to get the batter. The first baseman, seeing the runner from second had rounded third too aggressively, fires to the third baseman who tags him out. What have we got?
the play stands
The ball is dead once it hits the umpire, the batter is awarded first and the runner from second is returned to second.
The ball is live because it passed an infielder before striking the base umpire, but the runner at 3rd is protected to third base on the umpire interference and is allowed to remain there after the play.
The ball is live because it struck the umpire after passing an infielder other than the pitcher and no other infielder was in a position to make a play on the ball. The umpire is then considered to be part of the field, or as umpires say, we are how we are treated…like dirt, so the play, as weird as it is, stands. Two outs!