I think we must look to some form of automation, or crew of cutters relying on a foreman/overseer while they do nothing at all but supply the manpower, and that overseer dead or drunk, allowing them to continue unknowing.
You just can't get that far off the mark for the time it must have taken to get that far with the mistake, and not have known you were doing it unless some catastrophic distraction intervened.
Is there a thing of which it is said, "See, this is new?"It has been already, in the ages before us. Ecc 1: 9-10