That's the least understandable feature of all. The PF was a senior captain with over 10,000 hours, and a training pilot at that.
Just a guess, but I doubt whether these kind of errors (not closing thrust levers, or, for example, not setting altimeters correctly) correlate well with experience.
In fact, in our particular airline, I am led to believe that a significant proportion of our level busts involve training flights i.e., with at least one highly experienced crew member.
I also suspect that their analysis will not yield much helpful insight.
IMHO, the focus has to be how we improve the collective system propensity to fail safe.