Does the earth pin really not make contact until after the line and neutral, or are the contacts in the socket for the latter set so far back that earth continuity is assured first?
Don't know about the old ones which look just like BS 546, with a big round hole for the earth. These have a switch too, so you should not switch on the power until the plug is fully inserted.
The modern ones have the earth hole designed so that ut makes contact as soon as the pin enters the socket, whereas the other pins have a much longer way to go. I think this compensates for the short earth pin.
