Comment 10 for bug 1033932

> A crash on logout could involve an app failing to save a document or settings as it exits.

That should already happen before. gnome-session causes applications to ask for saving files etc. before it actually tears down the session. It's only crashes that happen during that teardown that are being filtered away here, and at that point D-BUS and everything else go away; there is nothing that an user or application can usefully do at this point except for exiting cleanly, and some applications just fail to do that.