I have seen him do that also. It seems that much of this is timing along with the obvious skills. The rate an object falls is pretty much the same no matter what it is, "If all objects which have equal weight fall at the same rate, then _all_ objects will fall at the same rate, regardless of their weight", so the timing aspect plays an important role in the shot. If you get the timing down then it's just a matter of practice, along with good eye hand coordination, "it's still hard", but most things have a resonable explanation.