The problem comes into play is when B1 deflects the Throw-in. This ends the Throw-in requirement. That is where BktBallRef states rule 9-9-3 no longer applys.
Many (including myself) would like the rule to state that if there is no team control, then a player can jump from frontcourt, secure control of the ball with both feet off the floor and be allowed to complete a normal landing without a backcourt violation.
