What about the cheese?
I would like to advise caution when chasing a single goose. It's still possible the pitots were not frozen over and the plane never entered extreme turbulence. We simply do not know anything yet. We have perhaps one, maybe two holes in the cheese, with certainly many to follow. We should keep this discussion academic IMO ..... trying hard not to cast, or giving the impression of casting, blame in any particular direction. I'm finding this thread very educational, and I would like to thank everyone for their contributions.