With all due respect, I've noted for a long time that you have a great deal of knowledge and experience and it is not my desire to diminish that in any way... I have enjoyed reading your thoughts for a long time and generally regard your thoughts as reasoned and well made.
But... this time you came across rigid that something could not be true because you have never experienced it... that of course is not an adequate argument that it could not happen. I've observed it... I noted it to my flying buddies when it happened because it was so unusual. I know the specific change that was made that relieved it. It is something that I experienced only once in forty years. It is likely that few every experience it, I did so by accident only because of an improper balance procedure.
I don't recall that any definitive explanation was provided explaining the dynamics involved of why it happened nor do I wish to argue the point between those who have and haven't experienced it based solely on observation... the world is full of people who see things differently and bully others to their perspectives... I don't want to do that nor do I wish it done to me. Peace.