Don't all jump down my neck here, a couple of simple questions.
Were the doors defective, that is, what specified limit in an "approved document" was not able to be met?
My very raw understanding, and I am very happy to be corrected, is that there were no breaches of the Supplemental Type Design holder's requirements. That is not to say that the door lock wasn't ineffective, but that the design criteria of the door was met and the aircraft was in fact serviceable to the design standards.
Whether the door lock was effective to DOTARS requirements is very different to whether the aircraft is airworthy to Type Design requirements.
MP.