I think the fear is that unless you watch someone work or see something they’ve produced, they can say all the right things but then be unable to really code without say a big huge helping hand.
I don't believe that it's possible to convincingly fake one's technical skills and experience in such an interview.
That said, I'm sure it is possible to fake not being an asshole, and I don't know how to reliably detect this. Doubt the FAANGs can either, though.