The way Oscar explains it, the enganchada (back cross, "hook") is executed in a more upright/vertical position. Tilting her axis forward at the moment of the back cross makes it a volcada. So, it's one thing with her axis vertical, and another when her axis is tilted forward toward the leader.
Mystery solved...mas o menos...
Mine looks like it might be more like milonguero ochos....and needs more work. Note that the clockwise one (on the close side) is fairly easy. The lead of the counter clockwise one requires a more rotational lead/entry (CC) to get her left leg to swing around behind her right.
Thanks for all of your interest and comments!