JF & G
One of the problems in a large organisation when the Flight test organisation (not just FTEs, pilots and others too) starts to "design fixes" is that the Design part of the organisation may be both offended and/or feel threatened. That will often be followed by a lock-down on communications, for fear of the "other side" stealing away "our job" - even if it's not a loss of employment issue, people get very attached to their jobs and for someone else to start doing it causes a lot of grief.
It gets worse when the FT organisation is designing fixes for things which are not, in the design organisation's mind, a problem. The course of action should be to prove the problem, not to say "oh, ok, we'll fix it then".
And before I'm accused of bias, let me say that the other side of the coin, which is basically design picking and choosing the test results it wants and basically circumventing the testing process thereby is just as bad. That way lies the FT organisation jealously guarding all the data, for fear someone will look at it "the wrong way".