The 8 volt decrease does not sound alarming. I just went through this scenario on my Shadow. Most (maybe all) pinsiders in my thread told me that small differences like that are within tolerance and should be ok. Well, except for one. The 5vdc was always wn important one because of supplying the cpu architecture...especially if it is low or under 5!

I have an LW3 and periodically have issues like this (no lightning though). Like mentioned already, reseating the ribbon cables usually fixes it. You need to make sure you do them all. No cheating lol, be thorough. Hopefully it is coincidence that it happened while lightning struck Try that please and report back.