Mr Angry
the ICAO definition of crewmember fatigue was given as:
A physiological state of reduced mental or physical performance capability resulting from sleep loss or extended wakefulness, circadian phase, or workload (mental and/or physical activity) that can impair a crew member’s alertness and ability to safely operate an aircraft or perform safety related duties.
His roster of 3 earlies including an extended 3rd day followed by a transition to a late would suggest a fatiguing roster.
I am intrigued to the type of operation you fly in. You speak of the need to sleep rather than it being fatigue however his roster caused that lack of sleep by the earlies that then meant he woke early (5.30 ish) on the day of his late duty. That is fatigue!