What I do depends on the age of the players and the skill level.
Boys'/girls' high school freshmen and above: I am going to side-step the pass; continue my throw-in count; and when the ball touches out-of-bounds past the Sideline extended I am going to whistle Team A for a Throw-in Violation.
Boy's/girls' Jr. H.S. and younger: Whether I catch the ball and restart Team A's Throw-in, or side-step the pass; continue my throw-in count; and when the ball touches out-of-bounds past the Sideline extended I am going to whistle Team A for a Throw-in Violation, depends upon the skill level of the teams and the players.
MTD, Sr.