Administering official may bounce the ball to the thrower, with the following exceptions:
- On all frontcourt endline throwins, the ball shall be handed to the thrower.
- If fans or bench personnel create congestion, or there is defensive pressure, the ball shall be handed to the thrower.
Administering official may hand the ball to the thrower (no exceptions listed).
Not very clear? Need more information? You're out of luck. That's all I can find regarding handing, or bouncing, for two-person IAABO throwin mechanics.