Rolling, thanks for some excellent points there.
I knew Kev way back but didn't know where he'd gone after the RAF. From your last point I guess my only reply would be that the RAF (and other, larger flying organisations) layer their supervision and orders to help manage the individual and help the individual manage him or herself under such pressures. The workloads you describe, though not considered the norm or wise when combined with day-to-day military aviation, are getting increasingly more prevalent in the current and predicted climate. Manpower shortages without a reduction in the 'ask' require sensibility and careful leadership. Operations have often brought such workloads you describe about the IB sector and I speak from experience. In those conditions we always helped each other out and spoke out, regardless of rank. Many times have I said, or heard said, "Boss, you need to get some sleep, I've got this!", followed by an understanding nod.
My view on this is that the organisation Kev was part of wasn't deep enough to provide that mutual 6th sense when things were diverging from the safe operating region. Kev was also undoubtedly very happy flying and in those circumstances it almost assuredly takes someone else to say stop. One word sums it up for me neatly: supervision.