It does not imply a false zero positive rate at all, because the hashes used are by necessity fuzzy, and even a completely benign picture can trigger a match.

Now they're saying that if the match is a false positive, it'll be screened by the human reviewer. But that means there's some stranger there potentially looking at my private photos (and, by the way, I wonder which country they'll be located in?). That's already completely and utterly unacceptable - you don't have to wait for any "future complications".