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.
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.