In my mind the most salient difference between code and natural language is that code has a formal semantics.
I’m still not entirely sure what people mean when they call a formal/natural language deterministic. As we’ve discussed, it can’t possibly mean that it has a single valid interpretation, since this is untrue of C code. If it means that code has a _precise set_ of interpretations, then I wouldn’t use the word deterministic for that.
I think you misunderstood. Determinism is the the difference between natural language and code. It's not about LLMs vs compilers.