Mike,
the pistol cannot be removed without cutting the cord; provided the cord is positioned correctly. For sure some ways to route the string do not offer any security, but I think the idea was to prevent the holster from being opened without cutting the string.
It's purpose was to tell at a glance that the pistol was "ready" for issue or use- I suppose.
There is also reported to be a picture in Bender's holster book,
but I can't find it today either.
Maybe someone will chime in with a book/page reference!