I hate to depart from the group think, but there's another explanation aside from a smart engineer getting carried away with their own brilliance:
They remarked how they spent a couple of days looking over the system which was complicated and creaky, they couldn't figure it out
Now it may be the case that they didn't really try to fix it and are just using that as an excuse, but OTOH, they may actually have been stumped despite best efforts.If the system really did defeat this smart engineer's days of study, then in my opinion, and the opinion of at least one discussion I've seen on HN, the software should have been rewritten. (IMO) this really needs more clarification before scorn is passed.