This will be an interesting outcome for us all at the pointy end for sure.
Agree 'sheppey' CRM to me is all a crock, (personal opinion)we have been doing CRM since the "Wrong Bro's" started this silly notion of man flying but we didn't coin that now huge industry feel good crap 'till more modern times so that had zip to do with it here I believe.
For crying out loud we are talking about the most basic of basic principles of flight, what the speedo says & it's No 1 importance!
Remember two pilots one crew, obviously not in this case.
Culture (as has been said) most likely had a big impact (no pun intended)as the fear of saying something stupid is ever present in a lot of cockpits.
Pilots are fiercely proud & no one likes to be made a fool of, right or wrong!
Wmk2