Seenitall - the flaw in the DC10 was not the cargo door (although that was a known problem, as evidenced by the Windsor (Ont) incident, and others before the THY crash), but the impact on control of the aircraft following any explosive decompression. The DC10 had far less redundancy than other contemporary wide bodies, and the control lines ran together through the non-reinforced non-vented floor. Any floor damage was therefore a significant risk. One of McDonnel's sub-contractors (IIRC Convair), had discovered the flaw in hull tests long before the aircraft first flew. The massive decompression associated with a cargo door blowing out, guaranteed loss of control of the aircraft.
However, those in the know, for whatever reason, chose not to take any action until after the THY crash. Contemporary studies in the aftermath described the FAA's approach during the DC10 development and certification as "fat, dumb and happy".
I would recommend getting hold of a copy of "Destination Disaster", which describes in great detail the DC10 development history, as essential reading for those in the "trust in those who know what they are doing" camp.