Fatigue-Item 4
Fatigue is a funny thing. I think all of us who have flown long haul and overnight stuff have had periods during a flight when we were really alert, and periods when the eyelids just can't stay open.
I remember a 707 early morning London arrival where I was almost asleep at TOD, and very awake making an ILS to minimums with an FD-105.
It's possible this crew had a simultaneous fatigue situation, and missed a lot of things.