The problem with your theory is that, as others have noted, the effect seems to happen with a red laser pointer as well. To interfere with the electronics, the

The problem with your theory is that, as others have noted, the effect seems to happen with a red laser pointer as well. To interfere with the electronics, the wavelength only has to as large as the band gap in silicon (as someone else has noted, around 1.1 eV). This means that IR light (and all visible light) can cause the interference too. A strong enough light source will lift a lot of electrons from the valence band across the band gap into the conduction band, effectively turning a transistor into a conductor for the duration of the flash. Since the sensitive part seems to be related to the power supply, it's quite plausible that this leads to the voltage fluctuations on the power rail.