But I think this has to be judged against an adversarial influx of LLM-assisted pseudomathematics slop vendors. A sorry-free proof in Lean (or Rocq!) whose top-level types check out is not good enough. You gotta check for compiler chicanery in all the private methods.
Or, alternatively: refuse to accept a Lean program as a valid proof. I assume LLMs are pretty good at Lean -> mathematical English in LaTeX.