@Franzl:
Allowing two F/Os, neither of whom had been trained in manual flying at altitude, to cross the ITCZ unsupervised with a known type-wide problem regarding UAS resulting in enforced manual control is in the realms of the unthinkable to start with - would you not agree? It's almost priming the system for an accident eventually!
Of course I'm talking with the benefit of 20/20 hindsight here, but even given that it has to be considered a spectacularly bad move. What are the "unthinkables" you are considering?
You make a good point regarding perception of acceleration, however if I've read the existing documents right then neither of these pilots had the fast jet experience you do that required this knowledge, and I'd venture to say that the only thing they'd be told to do regarding perception of acceleration and G would be to ignore it and concentrate on the instruments.