The plugin allows to submit the form when the session has already finished.
So if the anonymous access is not allowed and the session is expired or has finished by logging out, but when the page is still open in browser, it is allowed to submit the form, but the user can't be identified.
Steps to reproduce:
1. open the page with the form.
2. open another page in browser and log out from Confluence
3. submit the form on the first page
#43059 (http://artemissoftware.freshdesk.com/helpdesk/tickets/43059) - unknown anonymous, but it was me
#59567 (http://artemissoftware.freshdesk.com/helpdesk/tickets/59567) - problem Easyforms > User unknown