While they provided the questions that professors and LLMs were asked to respond to, they don't include any of the answers from either the humans or the LLMs, so there's no way to independently verify that the LLMs actually returned "better" answers.

Given the number of responses the professors were asked to rate (200 each), they probably graded them the same way that bar exam responses are graded: quickly and superficially. Not surprising that LLMs achieved higher scores in this scenario, since they excel at producing superficially nice answers that don't hold up under scrutiny.

Also...unless statistics has changed in the past 2 decades, the math in the charts doesn't math. That's probably why they're leaving out the actual numerical data. I also wouldn't be surprised if we learn in the coming days that the charts were AI generated.