Flt Det: My comment about the duty was based on the rostering phase. It was rostered at 12.30, the max. No room for hiccups. On the day, actual conditions caused to go over. My comment is: common sense says that rostering should always include a 45-60min buffer, especially on a 3 sector trip, to allow for hiccups. It became illegal at the last minute.
100%: It may be, I do not know, that fatigue is used as it was advised by the medical people. Perhaps it has a technical definition that fits in with legalese. Tiredness, sleepiness, exhausted are subjective. The more knowledgeable will tell us.
I still have a layman's interpretation that fatigued involves an element of muscle weakness. After intense exercise your body is too fatigued to give any more. To rostering, how can you be fatigued when you've been sitting down all day? Hence my wonder at a technical definition.