That “developing situation” started in Seoul, Korea when the pilots were planning the flight. In my opinion, the error chain began there with a poorly matched check pilot (trainer) and a weak Captain and crew. Most likely, the crew missed the fact that the ILS approach facilities were out of service for 28L and 28R. Knowing this, they would have had a flight across the entire Pacific Ocean to plan a non precision approach using the excellent Flight Management Computer to build an approach with alignment and glide path information that could have been autopilot coupled and flown to 300 or 400 feet. “Flash of Light”? I sincerely doubt it.
Bingo.
I don’t know. I will try not to speculate until the final report comes out. No one except the investigators can determine whether pilot error or mechanical failure is to blame yet.