It had to be an electrical switch problem. Every crappy Chinese LED flashlight I ever bought developed problems with the switch. The Chinese aspire to great things, but they can’t master the little details like a crummy switch.
Any programmer can tell you what went wrong.
Politics got into the design. They insisted that some well-connected moron be on the team. They used engineers who got into American universities by cheating on tests. They did little testing because it would imply the design was flawed if it failed.