[planteen]

Odds are the camera flash discharge caused electromagnetic interference (EMI) that disturbed your electronics rather than the visible light and UV radiation from the flash itself. Wafers are photo sensitive, but light is blocked by the packaging. Did you have decapped parts?

[abritinthebay]

God knows - it was a very old machine that I was taking pictures of. Caused a reboot (and was reproducable).

[prolepunk]

Could have been the same cause as the one that made Raspberry Pi 2 power off -- https://www.raspberrypi.org/blog/xenon-death-flash-a-free-ph...