All ULH operations have a fatigue element. It is a professional's responsibility to mitigate that fatigue element by inflight rest, professional competence and knowing your game. The last two items were NON existent.
Exactly! Well said.
Many professions have shifts where end-of-shift fatigue's an issue. But professionals handle this every day. We don't let a trucker excuse a crash because it was "end of shift". We don't let an ER doctor away with negligence because it was late at night. A process-plant operator that causes an accident cannot get away saying "it was a long day"
Professions have shift-lengths that were chosen to reflect the degree of fatigue. Ship watch-keeping is 6-hours-on 6-hours-off. Swimming pool life guards are supposed to rotate every 20 minutes.
If long haul flights are too long and the profession thinks it needs 3 sets of pilots that'd be a separate argument. I don't think we do.
Long Haul Fatigue might be a contributing factor but it surely isn't a mitigating factor or an excuse. That's only apologetics.