It is indeed not true, even omniscient beings can only produce probability distributions.

However it is not clear if quantum effects are relevant at a biomolecular scale. Some experts[1] suggest so but these ideas are considered fringe by the mainstream.

1. Sir Roger Penrose

I'm of the mind that randomness is only an approximation of complexity, if you're omniscient then randomness doesn't exist and everything is deterministic.

However it seems to me the deterministic vs randomness debate is of the same order as the existence of god(s) : we will never be able to prove or disprove it and we aren't able to make useful predictions out of the information one way or the other so we might as well just agree to disagree and move on.