Yeah, the quickest way to tell was to look for things that AI wouldn't include, like brown tips on flower petals or broken sticks that have the right fracture pattern and don't just fade away. AI tends to generate things that are very averaged/ideal looking. The textures of ai images also look wavy with like a 10-20pixel periodicity when zoomed in. The noise from real cameras is much more speckly.
I also got 20/20, but only because it was an A/B comparison. If asked AI or real on each image indlividually, I'm not sure I would get much above 65%.
Or to boost invoices on per capita contracts.