In Nautilus, right-clicking on a USB-External-Harddrive only provides the "unmount" option also. Selecting it doesn't remove the device from the left-pane of Nautilus NOR does it remove the device from Unity's Task-bar.
In 12.04, you could right-click on the device (from the Unity Taskbar) and select "Safely Remove". After that the device would be removed from the task-bar and you could then unplug it with some degree of confidence.
"Safely Remove" and "Eject" are missing from the Unity-Taskbar-Device-Icon's context menu. I don't know how Nautilus was before, but it too doesn't provide those options now (in its left-pane, under the "Devices" section). Nautilus may have been that way before; I cannot confirm that.
Yet, this bug report is specifically indicating the un-evolved behavior of the Unity-Taskbar-Device-Icon's Context-Menu, which seems to have un-evolved to a less-ensuring indicator of "whether it is safe to unplug your USB hard-drive or not".
In Nautilus, right-clicking on a USB-External- Harddrive only provides the "unmount" option also. Selecting it doesn't remove the device from the left-pane of Nautilus NOR does it remove the device from Unity's Task-bar.
In 12.04, you could right-click on the device (from the Unity Taskbar) and select "Safely Remove". After that the device would be removed from the task-bar and you could then unplug it with some degree of confidence.
"Safely Remove" and "Eject" are missing from the Unity-Taskbar- Device- Icon's context menu. I don't know how Nautilus was before, but it too doesn't provide those options now (in its left-pane, under the "Devices" section). Nautilus may have been that way before; I cannot confirm that.
Yet, this bug report is specifically indicating the un-evolved behavior of the Unity-Taskbar- Device- Icon's Context-Menu, which seems to have un-evolved to a less-ensuring indicator of "whether it is safe to unplug your USB hard-drive or not".