BOAC,
thanks for the reply.
The nature of the Why-Because-Analysis is that it only includes necessary causal factors. For analysing all the environment and conext of an accident this is a known shortcoming of the method. The other shortcoming is that it does not include dangerous situations/actions, that were not causal to the accident, although they were present, and should by all means be rectified (an example for this is the incorrectly assembled main landing gear bogie in the Concorde accident).
I'm curious about how Quito/Iberia turns out to have happened. And, of course, also Toulouse/Airbus.