[Nevadaref]

Originally Posted by BillyMac

I believe that if the player has it in his hands, and has the ball under his control, it's a live ball, even if the player is still inbounds, before going out of bounds, but I can be easily convinced otherwise, in other words, I wouldn't bet my house on it.

Consider yourself convinced otherwise.

2006-07 NFHS Basketball Rules Interpretations
SITUATION 9: With less than one minute to play in the fourth quarter, Team A scores a field goal to tie the game. B1, standing under the basket after the score, secures the ball and begins heading to the end line for the ensuing throw-in. A1 requests and is granted a time-out. RULING: Legal procedure. Team A may request and be granted a time-out until the ensuing throw-in begins. The throw-in does not begin until B1 has the ball at his/her disposal and the official has begun the five-second count.