That doesn’t matter, legally. They are hosting that data, they are the server it’s being served from, so they are legally responsible for that material. Being federated does not protect you from legal responsibility for things that your server serves up. Just because Lemmy can’t obey the law doesn’t mean it doesn’t have to (or result in potentially severe punishments). And it very much can. It can defederate from that instance.

Why do think google search has to respect takedown notices? They aren’t hosting it, but because their server returns it in search results, it’s liable.

Edit: they almost certainly ALSO sent one to lea.pet. We want to believe lawyers are greedy and evil and stupid. They are only two of those things.