The key here is having been assured by crew of arriving on time. That puts the onus on the airline, rather than the passenger.
A verbal contract; not guaranteed, but a source of consternation.
Now, what words are used to re-calculate the start (and stop) of the period as the passengers cross multiple time zones?
Is it not a greater wrong to force the flight to abort, than to cross a time zone as the zone as the sun sets