I initially read this as you proposing the pilot had insomnia-induced psychosis. Remember the U.S. pilot who had a psychotic break? I don't think that's what happened here at all, but did we ever figure out the story on that U.S. pilot? How often do people that age just randomly have a psychotic break without earlier odd behavior being noticed? Just wondering.
And I have watched all the air crash investigation shows mentioned and they are fascinating. I think some people here should watch them if it's not too upsetting - they show how often minor things can cause a big catastrophe, and how everything is not some crazy conspiracy - unfortunately, tragic incidents happen. Given how safe air travel is today, it's usually a combination of coincidental circumstances that alone would have never been a problem - and it frequently has something to do with pilot or maintenance staff error in response to a relatively minor mechanical issue. Humans are fallible - we've all misjudged confusing or unexpected situations. Not saying this case was pilot error - just saying that things don't magically go as smoothly as some people seem to think. Things are so safe now because we've learned from lots of unexpected problems.