Permissions on category vs file

I am a bit confused about the permission handling in this plugin.
I for most of my files defines a category witch have a role related to it, for example Editor. When adding a new file I assign that file to that category and expect it to have the same permission as the category. However the file itself is assigned “All users” to have access to it.

I think that the permission of the category should define the permission as long as you do not specify any permission on the file level. The permission on file level should be blank unless specified.