GNOME caches the administrative password differently than our sudo configuration
sudo to not cache the administration password, but when
GNOME is provided the password e.g. for opening a disk, the disk can be
remounted after it has been ejected without providing the password
This can probably be fixed by altering some polkit configuration in a live session (hence I mark this ticket “Easy”).
This affects both in 2.x and 3.x.