Pass hits coach, who is standing in his coaching box

[Smitty]

This is a scenario I had last night - I will try and explain it as best I can - hopefully you can visualize it. I want to confirm I handled it properly. First half, A1 is in their backcourt, dribbling toward their front court along the sideline table-side. I am trail alongside the dribbler. As we get to about halfcourt, there is defensive pressure and A1 throws a pass to A2, who is standing near the same sideline at the far end of Team B's bench, but the pass is moving from the inbounds side of the court to the out of bounds side of the court in the air, where A2 will have to reach over the sideline to catch the ball. While the pass is in the air, B's coach, who is standing out of bounds in his coaching box, is not paying attention to the pass - he is coaching his players defensively and is pointing to a spot on the court. His pointing arm is extended, maybe part of his forearm is over the inbounds side of the court. He is just coaching - again oblivious to the pass being thrown his way. The pass ends up hitting the coach on the arm - I'd say directly above the sideline. I blow the play dead and award the ball to Team B - as it touched the coach, who was standing out of bounds.

A's coach thinks this is a technical foul on B's coach for touching the ball, but my explanation was that if he interfered with the play intentionally, that might be a T, but he was just standing in his coaching box not even paying attention to the play when the ball hit him. To me it's no different than if I was in a similar position as the coach and the ball hit me.

Agree or disagree? I don't have my books with me, so if you disagree, please include a citation from the rule book.