Pilots are Pilots and they are humans , by nature susceptible to commit mistakes . I am pretty sure these guys knew most of the issues everybody is pointing out regarding basic skills , AP performance monitoring and so on .Maybe they would even be posting in this thread should it had happened to somebody else .
Even though it seems unthinkable at a first glance to "crash ...due RA failure ", a combination of possible events already mentioned by some previous posts , can set a scenario where many of us can commit mistakes that we might consider ourselves immunes. It is very easy to judge or stress out somebody else mistakes while we are seating in a bar with fellow pilots or posting replies for a thread....very easy .
Which of us drivers ever had that flight , with a long time friend in the cockpit , long chats and the situational awareness deeply affected .
" I was distracted I forgot ...".
The question we should make is "Why an aircraft with three pilots in the flight deck were not being properly monitored ?" . Well , time (and the investigation)will tell ......It was not the RA failure alone .