There is a difference but realistically, the possibility that it was your friends flight who was cancelled, probably 1/50. You have more chance winning a round of roulette then being on a cancelled flight with JQ.
Tell that to the punters in Darwin. They are less than impressed with the service/cancellation rate with JQ and usually don't have the option to jump on QF. Especially if JQ are the only ones operating on a route that was gifted them by QF.