Yes, but the percentage is low enough so that for all intents and purposes its predictable, especially if we can put in new fresh current data.

You cant take for granted absolute determinism, but from what I know thats precisely because of what you can take for granted: quantum indeterminism

The difference is that a coin toss or the weather is in principle determinate and predictable . A computer with enough data about initial conditions can predict it.

But when a photon hits a semi-transparent mirror , there is no principle that can predict if its reflected back or not.

But that means you're starting with the assumption that the person has free choice.

... — Babbeus

One uses the device to decide between yes or no to an action ( do i floss my teeth now , do i answer the phone, do i go there today) . Something like that. He substitutes his will for the indeterminate result of the quantum randomness. Nothing prevents him to break the rule.

Well...considering the theorem established the fact that a yes/no choice we make isnt a function of the past , its truly indeterminate, and you said to not make the mistake to say particles make a choice, then how de we define "make a choice " ?

Isnt the definition of "make a free choice" enough to be " indeterminate yes/no action" ?

I just realised that what I said is an actual experimental proof of the free will theorem (Kochen -Conway) that says that with certain assumptions we have as much free will as subatomic particles. https://en.wikipedia.org/wiki/Free_will_theorem