When recently flying a model airplane with friends, I was recording on a smartphone camera (I believe CMOS, 720p, 120fps), and saw, in one of the videos, a flash that was not visible to the naked eye, that covered the whole frame of the video. This occured at the same time that the aircraft collided, about half a meter from the camera. The frame appears to be almost pure white (#fefefc), with the left side (farthest from the brushless motor) having a slightly weaker white (#fefefb), although this is after the video was compressed. There are no visual artifacts or effects in the frames before and after.
The airplane has a single brushless motor, with an ESC (electronic speed control) attached. I don't currently know the specific specs of the motor and ESC, but can readily obtain them later today. The collision happened when the motor was still powered and spinning.
I am suspecting that the sudden collision while the brushless motor was still being powered caused some kind of electromagnetic effect (when it collides, the rotor is mechanically restrained by the ground), but I am not sure what actual effect is going on. I suspected simply a small electromagnetic pulse, but am not sure how it would affect only the camera module and not cause data corruption or crashes by affecting the CPU/memory. It's likely that the camera was set to a very high ISO/sensitivity in order to record at 120fps.
Could someone shed some light on how it was caused by the motor/motor controller itself, and how it managed to cause the camera to register a large flash?