The photographs below show a rather old 'Hercules' brand plug with the infamous wrap-around style of lid. This example is covered in dirt and for some reason is wired to 4 core flex, with the unwanted black core cut off.
These plugs required that the flex was passed through a hole in the lid before the plug was wired. You usually discovered this fact immediately after wiring the plug.
In this condition the plug is a serious hazard, as if plugged in to a socket outlet, the ends of the wire would be live.
When wiring such plugs, it is usual to cut the earth wire longer so that of the flex should be accidentally pulled out, the earth wire disconnects last.
Here, the earth wire is so short, it would rip out of the terminal before anything else.