This is a really badly written article. I didn't really understand what was happening until I read the Foundations article:

http://www.raspberrypi.org/xenon-death-flash-a-free-physics-...

Essentially, the component that regulates power to the CPU is a die-on-board package and due to the photoelectric effect certain types of high intensity ultraviolet are causing a voltage drop which crashes the board. Duct tape, as always, is a solution.