With past engineering-related coverups, I have seen credentialed, professional engineers raise quite a stink. Here in Arizona, the C.A.P. in the 80's is a good example (two professors at the U. of Arizona were loudly against it, along with others), as is the Missile Defense Shield today. There were (and are, in the case of missile defense) loud denounciations from professors, professionals, and organizations like the Union of Concerned Scientists, who has
prepared technical analyses of the testing program to illustrate what it does—and does not—show about the capabilities of the systems being developed. I have seen nothing similar (yet) regarding either the Pentagon or the WTC failures. Maybe no-one has done it yet, or maybe I haven't just haven't seen those that have been done, but I will probably remain unconvinced of any alternate theories of collapse until this happens.