Dan,
Your comment on how aviation incidents are reported reminded me of a presentation on operational safety that I attended a year or so ago. One slide in particular stood out, where it compared and contrasted the modern safety mindset of aviation versus the litigious mindset that can be found in the medical and other industries (no offense to medical professionals). The crux of the difference came down to how an incident was dealt with. In aviation, we ask "what" and "how" in an effort to determine root cause and make improvements. In medicine (in many cases), we ask "who" in an effort to determine fault and liability. One approach determines why something happened and provides a path to fix it; the other places blame and then moves on.
And with regard to threaded plugs, I cannot help but be reminded of a fantastic cartoon from a decades-old aerospace design manual. It holds true for
any threaded article installation: