returning inbounds...

[DRJ1960]

A1 makes a fast break layup and ends up legally out of bounds. B1 retrieves ball and is in the process of throwing the ball inbounds. A1 (returning to the court from directly behind B1) deflects the pass [a] after one of his feet touches the floor inbounds [b] while still airborne (both feet last touched OB). (Obviously, [b] results in at least a ruling of A1 making the ball have OB status).

Ruling?

(Everything I found assumed all defenders start the play in bounds).

What if A1 hit the ball while it was still in B1's hands while the hands were over in bounds area?