We can refer to these assumptions and speculations as a process of thought that leads them to their final report. This also helps us rule out what is not fact. If you think that the NTSB doesn't sit around a table for months after an accident or incident and speculate or make assumptions based upon fact, then you are down right crazy.
Hardly.
Speculation is not a part of any professional endevor; guesswork has no place in aviation.
To postulate and guess, with no facts in evidence, accomplishes nothing but fire pointless rumors...which on various boards thus far have ranged from UFO's to terrorism, to pilot error, to poor maintenance...all utter crap. Lots of talking heads spouting off their ignorance without any basis upon which to speak. But nothing of substance.
When an investigative team retires from the field to address the evidence they have gathered, the investigating members collaborate with industry experts and others to consider all the available data. Not simply guess based on no fact at all.
No, the NTSB, et al, certainly does not sit around a table for months and speculate (guess). Investigators spend months analyzing data, CVR recordings, measurements, material, evidence, eyewitness reports, crew and passenger testimony, and all other available relevant reports and information in order to make a factual determination regarding the events contributing to the mishap.
That has no bearing to a group of uninformed pilots (et al) blindly guessing as to what might have happend, without the slitest clue as to what actually took place.
I've been through the entire investigative process, starting with being first on scene to live testimony, to tearing apart the equipment to analyze the failure, to developing conclusions regarding each of the contributing factors. Not merely a classroom exercise, but the real thing. You've done this, I take it?