That may be true, but I think our current conception of free will necessitates some sort of nondeterministic mechanism. Our brains, being physical systems, appear to be entirely deterministic.
> unfolding of those deterministic processes
Doesn't sound free to me. Is a computer running a program exercising its free will?
If the physical world is non-deterministic, then there is nothing stopping a physical thing from having free will. If an 'outside force' can exert free will, why can't a physical thing?
It seems like the more we learn about quantum mechanics, the more things seem to be probabilistic than deterministic.
The physical brain being probabilistic fits perfectly with the idea of free will.
It does emphasise the point that any discussion based on a dichotomy between determinism and free will is fundamentally flawed, as randomness can be a relevant factor, so an anti-determinism argument is not necessarily a pro-free-will argument.
The important characteristic for randomness is that there exists no knowledge that, if possessed, would allow you to predict the outcome. In that sense, free will meets the definition of random.
In other words, not all randomness is free will, but all free will is random.
So yes, anti-determinism does not prove free will, but determinism would disprove it.