Help with a High School rule

[whitehat]

We were discussing possession after a catch of an airborne player on a similar thread.
There seems to be an inconsistency: A player is airborne in the EZ (like the forward progress situation described above), he is pushed back out of EZ while airborn to 1yd line. We have said TD because as soon as forward progress is ruled then play is over. I agree. Yet, what if that player looses the ball while still airborne as he comes down on the 1yd line? If the forward progress determines the TD then it should still be a TD right? If not, explain

Further, why is it a TD when forward progress is ruled in the above situation but not a TD, say 5 yards deep in the EZ as A player possesses the ball while airborne, is hit and then looses control of ball on the way down to the ground or as he hits the ground?