Plate Umpire Interference
The plate umpire should invoke interference on himself when he interferes with the catcher making a throw to a base.
Plate umpire Joe West exercised the rule on Aug. 19, 2008, in Philadelphia where the Phillies and Nationals played. In the seventh inning, Phillies’ center fielder Shane Victorino raced from first base to third base when a snap throw from Nationals’ catcher Jesus Flores sailed into right field. But Victorino was returned to first base because
Flores’ arm had clipped the chest protector of West, causing the wild fling. If Flores had retired Victorino at second, the interference would have been disregarded.
BTW- when the plate umpire interferes with the catcher who is attempting to retire a runner, if a rundown or subsequent throw is required to retire the runner, the ball is dead immediately and the interference is enforced which means the runner returns to the base he occupied at the start of play.
Umpires must be sure that the catcher does not initiate the interference because the runner got a good jump.