Good question. I can only guess from what else he told about his work that it was simply one of these cases where the younger staff was just not that well verse

Good question. I can only guess from what else he told about his work that it was simply one of these cases where the younger staff was just not that well versed with the old systems and mostly just managed to maintain them. Most of the stuff that was done in the early days of computing there wasn't formally documented as it was just a bunch of nerds who knew each other very well.* Apparently, when the company got rid of the big printers directly attached to the mainframes they just forgot about that one job, or maybe just removed the print job but not the one that generated it. By the time that happened almost everyone from the old team was already busy with other stuff, much higher up the command chain. * My uncle was actually a maths teacher, but right when he finished college there was absolutely no demand, so a friend already working there got him on board. He learned cobol while trying to figure things out there, reading books day and night...