> Humans writing code are also non deterministic

That's not what determinism means though. A human coding something, irrespective of whether the code is right or wrong, is deterministic. We have a well defined cause and effect pathway. If I write bad code, I will have a bug - deterministic. If I write good code, my code compiles - still deterministic. If the coder is sick, he can't write code - deterministic again. You can determine the cause from the effect.

Every behavior in the physical World has a cause and effect chain.

On the other hand, you cannot determine why a LLM hallucinated. There is no way to retrace the path taken from input parameters to generated output. At least as of now. Maybe it will change in the future where we have tools that can retrace the path taken.