[Manny A]

Originally Posted by lawump

The purpose of this interpretation is to clarify that a protected fielder's act of fielding a batted ball does not end immediately when the ball enters his glove, but rather that it also includes (fielder is still protected during) the throw (and follow-through) after the batted ball enters his glove.

For example, ground ball to F4 who has to dive to glove the ball. In the process of getting to a vertical base (in order to throw to F3 in an attempt to retire the B/R), R1 collides with F4. This is interference. F4, in layman's terms, has "fielded (the) batted ball," in as much as the ball is now in his glove, but under the interpretation above he is still protected as R1 collided with him before he was able to throw the ball (as he was getting to a vertical base in order to throw to F3.)

This interpretation was NOT meant to protect a fielder in a play like the one on the video in this thread where the fielder has fielded the batted ball, had an opportunity to throw the ball (but elected not to), then decided to chase after a runner in an attempt, presumably, to tag that runner, and then collides with a runner while chasing after another runner.

I still find it hard to believe that a fielder loses his protection when he starts running towards a runner, and another runner runs into him. By your parsing of the interpretations, the fielder gains protection as he's fielding the batted ball, loses it after he fields it and starts running towards the runner, and regains it when he starts his motion to throw to the other fielder. I can't imagine the interpreters feeling that protection is to be turned on and off willy nilly like that during the progress of a play.