Autocomplete results often feel like something spammers have been gaming for kicks, anyway. There are some truly bizarre ones that I can't imagine are a common search, but are probably someone's idea of funny.
Since autocomplete can be gamed, a spammer could easily start a defamatory rumor about a public figure. I don't blame the court for expecting Google to fix that "when it's brought to their attention." Surely that's not unreasonable.
The courts are increasingly expecting Google to add some human oversight to the SERPs, and I take it Google resists this because it doesn't scale - humans can only check so much so quickly. While I get their position, it's just not practical - especially for a de facto monopoly that gets held to a higher standard than smaller companies.