There is a variation of different play blasts here from my experimentation with the three animation shots. This first block out i did to establish the timing of the leaf falling.
The second playblast i added some rotation of the leaf, however i was not happy with it.
The third playblast i tweaked the rotation a little to make it a little mre realistic, however i am still not happy with it.
This playblast was to block out camera timing for shot 2.
I then added the leaf, however from the time it comes through the window, to out of shot, is too short.
i added some rotation to the leaf.
I changed the direction from where the leaf enters the window.
I slowed the animation down, however the leaf now takes too long to go off screen at the end.