It doesn't take a lot of armchair quarterbacking to put together the pieces....
Very true if any of us actually had the pieces to do so. None of us do so, we fill in the blanks if we, many do, need to fill that void and require a logical conclusion that will satisfy our desire for an answer.
As we only know what the press shares we can only make suppositions as none of us have any facts only, for want of a better term, "hearsay." So, the mind, disliking mysteries, fills in the blanks based on information/rumor/hearsay/opinions available. Nary a one of us possesses any facts, only what the media has provided, hardly the kind of information to make conclusions with. But, the mind/brain detests "blank" spaces and so we make it up as we go, filling in those "damnable" blanks as logically as he can.
There is a reason eye=witnesses are considered unreliable with supporting evidence. An "eye witness", who really only saw the vehicles separating after impact will tell the interviewer exactly how the collision happened, his mind filled in the unseen information. The witness will fully believe he saw what he, in fact, didn't.
There isn't a person alive who, at this time, can tell, reliably, what caused the implosion at this point in time. Design error? A collision with Titanic wreckage which would be operator error possible or another failure of some on-board equipment? On the outer edge of possibility, actions by passenger or crew, intentionally causing the implosion. My mind boggles at the possibilities not one of which can be excluded at this time. An in-depth investigation will provide possibly any number of possible causes or, with luck, the exact cause. Lots of time for supported conclusions.