Plain common sense. The same common sense that enabled people to discard the words of idiots on Reddit who claimed that ChatGPT was just Indians in a call center (a real talking point I ran into multiple times back then).

OpenAI does seem to be genuinely just high on their own supply for a little over a half of the manuscripts they released, but for the other half that is machine checked, either ((internal model)) managed to find a way to cheese 4 independent Lean checker kernels at the same time, and OpenAI somehow hasn't noticed / didn't report despite the heavy reputational risk, or the results are just plain correct. Go figure.

But even for the half that wasn't machine checked, there's an awfully big quiet regarding any defects in them. Given the insane schadenfreude potential and the highly potent David vs Goliat framing associated, one would expect any counterarguments to be frontpaged immediately, and be circlejerked to oblivion. Given that is yet to happen as well, go figure even harder.