Caz,
Last entry by me on this particular subject. It is becoming, like the breakfast issue, a bit of a red herring.
I accept that within 100 metres of the crash site there were witnesses who were in fog. No met observer qualifications needed for that.
What I don't know, is what the conditions were like, around and just above the aircraft at the optimum pull up point. This would be a considerable distance away from the impact point.
You know just as well as I do that in fog, you can have excellent flying conditions within metres of you.