Conversely, I wrote a few sentences in simple English off the top of my head (about The Sound of Silence, because they were talking about it on the radio this m

Conversely, I wrote a few sentences in simple English off the top of my head (about The Sound of Silence, because they were talking about it on the radio this morning) and it said it was "likely to be written entirely by AI". False positives in a plagiarism tool are pretty bad IMO. It should definitely skew towards "we can't be certain" rather than "definitely AI".