I think 8 top class engineers have a better idea what left on that fatefull day than anyone else
Although 8 experienced maintenance technicians (not 'engineers') might well have stated that there were no reported unserviceabilities within their trade area, that is most emphatically not the same thing as accepting an inherent design flaw. About which they probably had no knowledge.
As tucumseh has stated, the graphical relationship between probability and severity of harm is indeed straightforward enough. Whether it was properly complied with is another question.