WP Multisite Media Library File Deletion Oddness


I had a person delete all their images because they ran out of space. Not the first time this has occurred but I noticed something odd.

All references to the files are gone from the media library (expected) and most, but not all, of the files on the server are deleted (unexpected).

It seems like any file that was cropped in the WordPress image editor process remains in the server directory.

So I end up with a bunch of files named stuff like cropped-DSCN2086-7.jpg. They are still accessible through direct URL paths etc.

Anyone else see anything like this on their installation?