[laythea]

I don't think that is the case. Given the types of failure we are talking about, this would be documented as part of the design process.

All it takes is someone from the FAA to read it and think about it and act on it. That is the role of the FAA.

Now, if it wasn't on the design, then you may say Boeing is mainly to blame. If it was documented, but not rejected, then the FAA is mainly at fault.

Ultimately though, the FAA has the responsibility.