Do you consider the implementation of such specs by another human to (always) be correct and deterministic?
Heck, if I reimplement something I worked on a month ago it’s probably not going to be the exact same. Being non deterministic needn’t to be a problem, as long as it falls within certain boundaries and produces working results.
> Sometimes the interpolated detail is wrong (and indeterministic)
... You consider incorrect, non deterministic results to be "reliable"?