Weird spam reports from this instance?

Hi Lemmy.world admins! I'm an admin over on lemmynsfw.com. We've been getting a handful of reports on posts on our instance from lemmy.world users, all with the subject "Spam or Abuse", and in all but one case the post was neither spam nor abuse.

Could there be something weird with federation going on? It doesn't seem like malicious reporting and it doesn't seem to be following any pattern that we can tell. It's just weird.