Closing down on a play that is going away from you that you whistled for a foul can make you look way more connected to the play than standing still or immediately moving toward the scorer’s table.
Maybe you were only 15′ from the play when you filled your Fox 40 up with carbon dioxide but by the time coaches, players and fans “find” the whistle the action could have continued 30′ away from you.
By closing down on the action the calling official will appear closer to the play and that will translate sub-consciously to more confidence in your decision by those watching. At least that is the theory.
In the clip below the center official closes down about a third of the way toward the action after sounding his whistle, then pauses and counts the basket and then finishes his paperwork. (Who the shooter is.)