Obstruction question

[goodbook]

B) Obstruction - "The act of a defensive team member that hinders or impedes a batter's attempt to make contact with a pitched ball or that impedes the progress of a runner or batter-runner who is legally running the bases, unless the fielder is in possession of the ball, is fielding a batted ball or is about to receive a thrown ball. The act may be intentional or unintentional." For clarification purposes, "1. The defensive player must be in the process of catching the ball and not merely positioning, waiting for a throw to arrive. 2. The act may be intentional or unintentional."

"about to receive a thrown ball" this is my problem with the call