One earlier poster made, a tongue in cheek, comment about "a lover's tiff".
Obviously nobody is implying that this was a factor in this case but it does draw out one important CRM point. Romance has no place in the workplace, particularly in safety critical and demanding environments like an airliner moving at some 600 mph through congested skies.
I am not an airline pilot but to my eternal shame as a mere PPL I have literally lost it with a passenger, my then girlfriend, while flying just outside Class D airspace on a long cross country flight. The niggle factor got to me and white faced with rage I found myself 800 feet below my altitude and some 30 degress of course. I had completely lost situational awareness. I should not have flown at all that day and certainly not with her.
Rage of the cold white type is a form of madness and I believe it can overtake anyone. I think we should cut this Captain some slack.
It shouldn't but it could happen to anybody. We are all humans, airline Captains included, with the emotional and physical foibles and baggage that goes with that.