Maybe it's the spectrum - it is probably White LED technology, which is a blue LED on high intensity. I'm still waiting for "purple chip" LED bulbs, but it seems they aren't sold yet.
With a camera you won't be able to detect all flicker. You must know, all those LED bulbs have some flicker. Mostly it's 100/120 Hz. It can be very small so that you'd need a photodiode setup to reveal it. Trust me, it is possible that super tiny flicker can trigger symptoms (own experience).
Those LED bulbs can have all sorts of flicker. Wavy, rectangular, noisy. 100 Hz, 20 kHz, and whatnot. It's a gamble, and even the "flicker-free" ones do flicker. The lists of "flicker-free" bulbs on some webpages are not accurate. I bought some of those bulbs, and they do flicker in some way or the other.