These "variables" are merely statistical
approximations of physical laws in action.
The whole science of biology is just that too.
As for the question posed in this thread's name:
My answer would be: Yes, it appears to be so.
Of course, you have to understand that "duductivly
ruled out" is only a probablistic(like everything
else in the Universe) term refering to deductions
connected to current reasoning systems in turn
connected to observation. You see, "free will"
implies lack of laws, at least according to
the reasoning systems science currently recognizes.
As for QM, stop using it as some sort of
magic wand for any belief starting from God
and "down to" free-will. This is pathetic.
Live long and prosper.