How do you know you can discern AI vs human with high probability? You need some external source of truth to judge that, otherwise all you know is that you can discern bad, obvious AI. See also https://en.wiktionary.org/wiki/toupee_fallacy
I can say that my false positive rate is very low which is enough in this context.
I can say that my false positive rate is very low which is enough in this context.