You make the call

[SamIAm]

I'm going out on a limb here - If the ball came loose as a result of the contact not because the player completed the throwing or pushing motion, the player did not complete the throw and there wasn't a throw to be unsuccessful, thus making the try dead (along with the whistle). To then re-acquire the ball and complete the throwing motion seems legitimate. Count the basket.
I admit it might not be a simple call whether the shooter completed pushing or throwing the ball verses the ball coming loose prior to completion.