Not sure I'm buying this concept.
The head is still on a fixed axis to the shaft, so to suggest it can take an independent path to that of the shaft is not so.
Also, I suspect that upon striking the animal, the force of the head "loading up" back upon the insert would bind up the rotation - particularly if they are made of aluminum.
I would like to see slow-mo film of this arrow through some bone reinforced gelatin to see what is really happening.
Just my opinion here...