Traces of manual editing
Broken grammar or duplicate words left after changing a sentence on the fly.
"We moved the parser to a separate server because the old one lacked RAM when building dictionaries. SSL certificates should connect automatically."
"Moved the parser to a separate server, because the old one was lacking lacked RAM when building dictionaries. SSL certificates should connect attach automatically."
A machine has no mouse
A neural network generates text linearly. It doesn't have a cursor, it doesn't highlight words with a mouse, it doesn't jump to the beginning of a sentence to change a verb to a more precise one. Therefore, it leaves no traces of such editing.
Humans write non-linearly. They might type "should connect", then change their mind, place the cursor, type "attach", but forget to delete the previous word. This is a structural bug of the "brain-hands-keyboard" interface, making the text a 100% organic artifact.