The question is, which laws of physics, and are the interaction between those laws of physics, interactions we already know, or new ones we have not discovered yet?
Otherwise we might as well say consciousness follows the will of God.
Why? The engineering definition of deterministic implies predictable outcomes given a known internal state. Are you suggesting that we're already at the level where we can accurately and fully measure a human brain's internal state?
That does not mean that we cannot discuss the likelihood of each explanation, keeping in mind that both explanations could be incorrect. We have Drake's Equation even though, for all we know, nobody has ever seen an extraterrestrial life-form. We have flight because nature demonstrated flight to us: nature continuously demonstrates the capability to evolve quantum machines (e.g. the nose and various other organic processes[1]).
Finally, the engineering definition of determinism is not the only definition.[2]
[1]: http://www.bbc.com/earth/story/20160715-organisms-might-be-q... [2]: https://en.wikipedia.org/wiki/Deterministic_system_(philosop...