Hands are only a give away for bad AI art. There's no shortage of examples with great hands (especially when using features like Stable Diffusion's ControlNet, which allows you to give hints to the AI for the shape that something should match). Just so many people posting AI art generate once or twice and post that. If you're more selective and selectively regenerate, you'll be able to get much more believable results.
This is also a rapidly changing area, with the most cutting edge AI being way better than something from even a year ago. Used to be that no AI could do even remotely believable text, but in recent weeks, I've been seeing many examples of AI art that got small amounts of text perfect.
I don't think that's necessarily a dead giveaway. Because there's been controversy about AI art that added watermarks. The controversy being because it implied the AI was scraping images that it definitely wasn't allowed to use.