Right but where were they resurrected from? A database (local or otherwise) that secretly keeps deleted photos forever? And if so why is it keeping them forever instead of actually deleting them?

I imagine the database corruption prevented the permanent delete from the Recently Deleted folder that's supposed to happen 30 days after you mark something as deleted.

If it behaves anything like the Mac Photos app, then it's using hard links for things like importing photos which can lead to bugs like this if the corruption led to them losing track of one of the hard links, since you have to delete all of them to actually delete the file.

That’s a reasonable explanation. Still, they need to be a lot more transparent about what happened and confirm explicitly that those files are deleted now and that in general, files are permanently deleted. I feel like all too often, Apple just stays silent on issues and avoids any semblance of customer support, and that needs to change.

Most likely the "secret database" is just the filesystem. Keeping things forever is the default behavior of filesystems.

A photo library application is just a database pointing to files in the file system. In some cases photos were deleted from the library database without being deleted from the filesystem. That's the bug.

The consequences are that: 1) the photo appears to be deleted to the user, who goes by what the application tells them 2) the photo appears to be deleted to the application, who goes by what the database says, and 3) the photo miraculously reappears when the filesystem is re-indexed by the application.

Pressing 'delete' in Photos, by default, moves it to the Recently Deleted album, and uses a record in a database to schedule deletion for later.