Possible Bug?

I'm not sure if this is a bug or what:

If you add a contact with a phone number, add that contact to your favorites list, then delete the contact from your contacts list, the phone number remains in the favorites list without the name.

Is this supposed to happen? Maybe they don't want people to delete a contact, forgetting that the phone number in it is important? Or maybe the favorites list only contains pointers to phone numbers and not the whole contact, so they accidentally made it so this happens?