Rule Clarification to a play we discussed

[A Pennsylvania Coach]

I've been reading this thread with great interest. Last year we led 48-45 with :05 to go. We had a foul to give, and I thought I was clear in the timeout that we'd only foul when the player's back was to the basket. I'm sure you know what's coming next. Yep, we fouled on a three-point attempt with :01 left. Amazingly, the girl (they were the visitors and we had a pretty good crowd) hit all three. Well, on the third attempt the opponents had all four of the shooter's teammates in lane spaces, so I had my PG down in front of my bench all by herself. As the third free throw went through the net, my player grabbed the ball and fired it to the PG, WITHOUT GOING OOB FIRST. This is exactly the play that would make this a problem, because without a whistle, our player would've gotten a shot away before a five-second count would've expired. Fortunately for us, the official blew his whistle and called for a "do-over". We inbounded and went on to win in OT.