Dan/Topbunk,
Excellent posts and the main points very well made. However, to keep the thread accurate. This was a 4 man crew, the operating crew having just had 38 hours in MEL.
I do not know the crews previous rosters but having done 90+ hours in 28 days then the Captain was probably fairly fatigued. Like it or not, given the present climate and rules, this is part of ULR flying. As a professional one is in a position (obliged) to mitigate this fatigue risk. How that is done is up to the individual. As a starter for 10 though I would suggest that recognising that you are not always at your peak and therefore a more pedantic approach to SOPs may not be a bad idea.