Strange happening on Throw-in following basket...

[JugglingReferee]

Originally Posted by CMHCoachNRef

A1 takes the ball to the basket for a lay-up. He makes the lay-up. His momentum carries him off of the floor. B5 gets the ball and attempts to take the throw-in. As B5 is releasing the ball, A1 leaps from behind B5 and slaps the ball. Keep in miind, A1's momentum carried him off of the floor. What do you have?

Because you said "as B5 is releasing the ball", I take it to mean that without the actions of A5, the release is imminent, but still in B5's hands. Contacting the ball with the ball over OB is a technical foul. Bad play by A1.

If the ball had already been released, then it is an OB violation on A1. B's throw-in, without the use of the endline. In this case, nice play by A1. I don't have a penalty against A1 because A1 was legally OB.