Given that so many humans these days write like they're assembling a collection of pre-made clichés and currently trendy phrases together, rather than even trying to express themselves with anything approaching originality, I reckon the task would be difficult. But more because of the number of false positives amongst the human writers than slip-ups by the silicon ones.
If it is wrong (looks right, but is unsound) it is likely written by GPT.
If it is wrong (looks right, but is unsound) it is likely written by a Human.
