My best guess is that neither pilot saw the other aircraft at any point.
Not
never, but too late I think. The helicopter was climbing out, has most likely not seen the Piper prior to takeoff - and probably never did afterwards (btw. Devil: there is not enough room for a clearing turn - correction: maybe enough room, but you'd be busy not putting your tail in the fence, rather than scanning for traffic).
To the best of my knowledge Libertys AStars are flown left seat (?); leaves a big blind spot to your right-aft quadrant.
Putting everything together: speed of the airplane, climb speed of the helicopter (indicates that the Piper pilot has not seen the helo take off the heliport - unlikely that the helicopter was underneath the Pipers wing during the whole climb-out, considering the climb speed of of an AStar) and the fact that the Pipers right wing instead of the left wing got cut off, indicates that the F/W pilot tried to bank away in the last second.
Yep now I did it, I
guessed what happened based on what we know. As for determining if that's what really happened and who's fault it was, I leave that to the NTSB.