Note the definition of 'free will' here is specific: fundamental particles future states cannot be purely a function of the information in their past light cones and so only 'they' can fully determine their future state, and this is not the same thing as them having random number generators; they truly are free
And despite the claim to the contrary, his definition of "free will" isn't appreciably different from randomness, only he uses the word "randomness" to mean pseudorandomness, so he sticks the term "free will" on true randomness.
An interesting contribution to quantum physics, presumably, but not a proof of free will.
1. "It follows that we cannot prove our Free Will assumption – determinism, like solipsism, is logically possible."
So not a proof of free will.
2. "Although we find ourselves unable to give an operational definition of either “free” or “random,” we have managed to distinguish between them in our context, because free behavior can be twinned, while random behavior cannot (a remark that might also interest some philosphers of free will)."
I stand corrected. This IS a meaningful distinction from pure randomness, after all, as entangled particles don't behave randomly with respect to each other. Though I still disagree with the name "free will", as that makes it sound as if there's a conscious will behind it, which the authors make it clear that they don't claim.