From my reading the German court's ruling is that Google are responsible both for claims they made up and claims they rephrase from somewhere else. Because the claims appear as a statement of fact made by Google. If they showed it as "User X on site Y claims Z" they would not be held responsible. Because that's how search engines are understood to work. If they make a wrong quote, they would be responsible for that though.

So my understanding is their unreliable AI summaries are a legal liability for Google in Germany and people can request corrections through the courts.