Speculations are going to take over the discussion, but among the possibilities
Don't encourage speculation by listing possibilities then !
If you want speculation and enumeration of possibilities, go watch the journalists on TV making another hash out of aviation reporting.
Can we please, for once, show some restraint on PPRuNe, and a little bit less of armchair investigators racing to be the first one to name what is later found to be the cause.
Remember, journalists read PPRune ... so let's not feed the devil nonsense that they will then regurgitate as "facts" from "reliable sources".