It understood they would been unfit for duty at one stage even if their plane had been airworthy
.
Which it wasn't and the crew knew it.
The flying captains responsibility is to liaise with engineering, (possibility of a test flight, ground run etc), and work backwards from the 'not before' time given him/her. The comfort of, transport of and communication with pax is the responsibility of the ANZ airport manager or the appointed agent.