Trying to find the 'real cause' is a fool's errand, because there are many places and ways to avoid the outcome.
I do take your meaning, reducing speed and following well established rules would have almost certainly have saved them.
0. PDF: http://www.leonardo-in-flight.nl/PDF/FieldGuide%20to%20Human...
Amazon: https://www.amazon.com/Field-Guide-Understanding-Human-Error...
Amazon: https://www.amazon.com/Field-Guide-Understanding-Human-Error...
Older PDF (paperback is well worth it, in my opinion): http://www.leonardo-in-flight.nl/PDF/FieldGuide%20to%20Human...