Where is Throw-In Spot?

[IUgrad92]

Team A makes field goal. B1 grabs the ball, jumps out of bounds on baseline, and heaves the ball up the court to B2. The throw is too high, does not touch any players and goes out of bounds on baseline at the other end. Where is the throw-in spot for team A, where the ball went out of bounds or back where B1 threw in?

We've all had this situation, but usually after a time-out. Not sure if this situation is different or not. Field goal is made, which makes the ball dead, but the clock is still running.

Please give NFHS reference.

Thanks

Brian