Comment 8 for bug 543042

Martin: I guess you can simply run 'sudo killall polkitd', and it will forget your authentication.

One would have to check whether gvfs actually redirects POLKIT_ERROR_CANCELLED to G_IO_ERROR_CANCELLED, and if so, then add it to the ignore case in Nautilus. Or simply add that condition in Nautilus, and see if it works! If it's not the case, it would be worth considering canceled authentication as G_IO_ERROR_FAILED_HANDLED, which seems to be intended for this case.