Ouch IO that's a harsh statement.....
I m quite sure many of the IR pilots who've crashed over the years thought of themselves as diligent pilots who would not make mistakes such as the ones they read about on forums and in other publications, yet they crashed.....
The one thing we cannot change is our humanity, and therefore the realization that we can only limit the risks of making a human mistake, never take it away.
It's what brings me here and keep me humble
In your analysis of course you are quite right, although you keep maintaining the impression it was in full IMC, but i seem to remember from postings here (one being the NTSB but if memory serves me right also fluglehrer) that there was at least some visibility.
A partial visibility as opposed to full blown IMC would explain the mistake more than a full blown IMC.