Foul or incidental contact?

[Buckley11]

Sitch: A1 and B1 are going for rebound. B1 falls to floor(not fouled, just lands awkwardly). A1 rebounds ball, returns to floor, spins towards basket and trips over B1 who is lying on floor. A1 then:

a)falls to floor holding ball.
b)releases ball to shoot while falling.
c)loses ball and B2 recovers.

What do you have? Here are a some contradicting thoughts on this play. 1)Is B1 "entitled" a spot on the floor, even though he does not have "legal guarding position"? 2)Once A1 has the ball, isn't the impetus on A1 to avoid contact? 3)Does "verticality" apply when a player is "horizontal"...... (you don't have to respond to 3, I had a weak moment and thought I would be a smart a$$)

I am, however, looking forward to your thoughts..

[Jurassic Referee]

Originally posted by Buckley11
Sitch: A1 and B1 are going for rebound. B1 falls to floor(not fouled, just lands awkwardly). A1 rebounds ball, returns to floor, spins towards basket and trips over B1 who is lying on floor. A1 then:

a)falls to floor holding ball.
b)releases ball to shoot while falling.
c)loses ball and B2 recovers.

What do you have?

.
a) Travel on A1 when he hits the floor.
b) No call.Pivot foot lifted and ball shot before pivot foot returns to floor.
c) No call again.

The exact same concept is used in NFHS casebook play 10.6.1SitE.