I remember that when I was a Type/ Instrument Rating Examiner on the B757/767 (I'm retired now) the 2-engine go-around was frequently performed untidily in the sim, so much so that I included this procedure in my
'How To Do Well In The Sim' paper. It's disappointing to learn that crews are still getting themselves into trouble flying this manoeuvre.
Have not read the whole report in detail but was this really a (subtle) case of some form of pilot incapacitation?
That's why there are two pilots in the cockpit, both of whom should be adequately qualified, experienced and not fatigued.