Document does not delete

I am hoping someone can provide insight to the following questions.

Action being done:

Tried to delete a document (birth certificate) added by someone else on a birth certificate having restricted update and delete.

Person's assign role code matched one of the role codes listed in 'Restrictions'.

Application appears to accept the deletion; but document still appeared in the list.

Question(s):

1. Why when the minimum number of document for the document type was set to 1, did the Error Message you must have at least one attachment appear even when there was multiple documents with unique file names?
2. Why when the minimum number of document for the document type was set to 0, did the document not actually delete.