So seems that the more experienced F/O ,most likely in the LHS ,was trying to fly the a/c but also having to help out the inexperienced F/O (800 on type)
with dozens of chimes /bells/ messages etc...and ended up distracted and eventually losing control.
as we all know rule 1 : fly the airplane.however these guys were dealt a bad set of cards..particularly the less experienced F/O..they just got overwhelmed with the situation...one which they were not trained to cope with.