A rules question for non-umpires

[MTR]

12.17.1 When an umpire, or a base runner not in contact with a base, is struck by a fair batted ball after it has passed an infielder (other than the pitcher), and, in the judgment of the umpire, no other infielder had a reasonable chance to make a play. - THE BALL IS LIVE.

Actually, NCAA 12.4.3, 12.6.3 and 12.17.1 reference a "fielder" as opposed to an "infielder". This is an important difference in the FP softball game.