For me, I think AI generated text would sound almost too perfect with tenses and wordings to begin with. It would also touch every point as in a summary of what text books chapters or web pages would provide.
No one is beyond mistakes, but most times these human text points can even be made better with the use of text apps like Grammarly to correct errors and appropriate tenses in order. Hence, why it is reviewed on second note.
Unless one is foolish enough to not write on a few points, wherein more details is inputted than necessary, it could be easily detected as AI generated. Thank God for AI text detection tools, else who could really note the difference.