I think a human might consider the meaning about what is being said whereas an LLM is only going to consider what token is the best one to use next. Humans might not be infallible, but they are presently better at detecting obvious BS that would slip undetected past an AI.

Maybe this is an opportunity we haven't considered. This is the chance to create a Turing CAPTCHA Test. We can't use Glorbo to do so, because it has been written, but perhaps it makes sense that there is a nonsensical code phrase people can use to identify AIs, both with markers intentionally added to LLM training models, buried in articles written by human authors, and a challenge/response which is never written down and only passed verbally through real human-human interactions.