Crews might also be fatigued, and it's a Commander's decision whether to use discretion. Following good CRM principles they should take into account the rest of the crew's fatigue and other conditions but it's one of those decisions resting on the four-striped shoulders.

Bad weather, multiple approaches, holding, diversion, fuelling, and facing more of the same on the way back might well lead to a decision that the state of the crew means discretion is a bad idea.

"A superior pilot uses his superior judgment to avoid situations which require the use of his superior skill." (Frank Borman)