Team A scores a basket, field goal or live free throw. Ball goes through ring. Team A begins to set up full court press. Team B does not immediately possess the ball.

What are Team B's responsibilities and time contraints by rule to begin inbounding in this situation?

What are the official's responsibilities (especially the old lead's) as far as assisting or not assisting Team B get play started again?

Or more to the point:

Does the referee on the inbounding baseline handle the ball?

If you see Team B not trying to get the ball out of bounds for the throw-in, you immediatly start you 5 second count. You do not have to hand them the ball after a made second (two shot) or third (Three shot) free throw unless the ball becomes dead for some reason....like subsitution on the free thrower or time out. There are a couple of other situtation too. As far as the old lead's responsibility, I would just start the count, team b knows that it their ball out of bounds. The couch should be screaming about that time! See Rule 7 Art 5 & 6

If the ball is clearly not "available", such as that it bounced off someone's foot into the bleachers, you don't start counting till B has reasonable position on the endline with the ball. But if they're just standing looking at the ball, waiting for someone else, or if they are actively arguing about it, start counting. Definitely in this situation DO NOT handle the ball.

Casebook play 4.41.3 should help you out too.

I agree rainmaker, left that out about the ball rolling away or off another player......I would at least give them a chance!

Said another way.
Do not penalize A for hustle and good Defense. If they are pressing, and standing around with you not having a 5 second count, then they are getting a freebie to set up to get past the press. 5 second coun starts when ball i made available. It went thru, and hit the floor (and it hasnt gone someplace funky) start your count.

Too often w e fail to reward good defense.