I was also the cause of a delay on one occasion.

A QF domestic flight on which I took quite regularly, regularly enough I knew some of the Flight Attendants, boarded was seated in 1D in J class and just as the door was about to be closed I got a call that my wife had gone into early labor and was being admitted for an emergency caesarian.

The lead FA was very helpful in getting things arranged for me to disembark, but it did delay the flight somewhat.

Took the flight two weeks later and got the same lead FA who of course wanted to see the photos of the addition to the family.