If there is a problem with one of the components and there is tight production control, a fraction (possibly 100%) of these components could fail in a tight time band. We've had these sorts of issue over the years.

In one case a normally reliable product started failing, shortly after purchase. The replacement parts also failed. Typically, the replacement parts arrived already failed. It took a few weeks to sort this out, but the problem was traced to a single employee on the production line who was not following surface prep procedures. All parts that he produced during that period would fail and the replacement parts came from that batch. After a certain number of days, the part started to physically break down. To my knowledge, all prior and subsequent (to the bad batch) units are still working.