This occurrence highlights the importance of flight crews declaring any instances of acute fatigue and stress-inducing circumstances that may have an impact on their flying performance. Operators also need to remind flight crew of the importance of their decisions with regards to their fitness to fly.
A typical management style approach highlighting the fatigue onus being on the flight crew member (who is in the most difficult position to identify their level of fatigue) without any mention of work schedules/rostering/work practices which can contribute to said fatigue. It really is a joint responsibility but these days it seems crew are out on a limb all on their own these days when it comes to managing the 'f' word...