One of my college mechanical engineering professors was a former NASA engineer involved in determining risk and investigating problems. He gave a gave a lecture & led a discussion on the Challenger O-Ring case (and I have since read a lot of the reports). As you mentioned, the CMU lecturer wasn't even close to the real story. But it also ins't so simple as to say 'managment didn't listen'.

The engineers knew what was going to happen with a fairly high degree of certainty - enough that the launch shouldn't hvae happened. Then they turned to management and tried to present their findings. Clearly the business guys didn't want to be the ones to hold up the launch, they had a strong incentive not to. So the engineers had to convince them why the company should basically stick its neck out as one of hundreds and hundreds of vendors and stop this launch. The engineers didn't do the best job of communicating the certainty of the problem, the magnitude of the problem, etc. So it was a little bit of both.

That lecture was probably 8 years ago for me, but it definitely left a lasting impression. Today I work on systems that truthfully are more complicated than the space shuttle and also have a lot more lives at stake. "Intellectual honesty" is a phrase I live by. There have been times I fucked up some math and knew we needed to fix something - even though it would money and delay, but I stuck to my guns and made sure it happened. The alternative is too likely to lead to disaster. It keeps me up at night, and those are the near misses. I can't imagine what that guy went through knowing they almost stopped it, but didn't.