I'm not 100% sure, but I think they're referring to the nines of reliability. Something, such as web hosting or server time, is typically deemed as "reliable" when it is 99.999% available as intended. I think what they're trying to say is that a video doesn't need to be reliable at all. As long as you can execute something once or fake it realistically, the video is good enough. For real-world application, though, you need at least 99.9% reliability and, arguably, you'd need 99.999+% for people to accept it.

I might be totally off, though, since I've never heard of the nines being used in the context of autonomy but it does make sense in context of the conversation being had.