The point is, they "proved" the Collatz conjecture. You would not know they exploited a bug unless you actually went and dug into their proof. Can we be so certain this has not happened within the millions of lines of Navier-Stokes? In an ideal world, our proof assistants would be more battle-hardened by now (recent exploits deny this), our AI better aligned (their tendency to cheat at tests denies this), or their handlers more responsible (the Hugging Face incident denies this), but the reality is more complicated.
At this point in time, we really can't be confident in accepting proof certificates without any human eyes on the script that generated it. I still have 95%+ confidence in this particular result being trustworthy, but a precedent of blind faith is guaranteed to end badly.
This person knew they did not prove the Collatz conjecture and others independently figured it out within hours. Not sure this is at all relevant, other than pointing out how trivial it is for the community to understand errors in lean4.
It was trivial because the Collatz proof script is literally 1000x smaller than the script for Navier-Stokes and involves no advanced math. And they found the bug by... manually inspecting the proof script. Maybe we should do the same for Navier-Stokes before declaring the matter settled?
Not only that, but there is a very fuzzable tell of something funny in the Collatz proof script (`CommandElabM`, i.e. metaprogramming). We may not at all be so lucky in other malicious scripts, especially if there are still kernel-level bugs in Lean.
At this point in time, we really can't be confident in accepting proof certificates without any human eyes on the script that generated it. I still have 95%+ confidence in this particular result being trustworthy, but a precedent of blind faith is guaranteed to end badly.