Comment 191 for bug 236901

How can shutdown be aborted after the quit-application-granted notification goes out? That notification is only supposed to be sent when all quit-application-requested observers have agreed to allow shutdown to occur.

Basically it's supposed to be beyond the point of not return at that point in the shutdown process. If this isn't the case and shutdown is somehow aborted after a quit-application-granted notification is issued, a number of add-ons and components will get into a bad state.