Speaking of Sydney, one time on a Quantas flight from there back to SFO the 747 had a problem with one of the engines. I was sitting up front in business class watching the flight crew and maintenance people shuttle in and out of the cockpit. The captain was a woman. The FO was a man.
All of the announcements were made by the FO only. Finally, the end result was "I believe I've found a way around the problem" as in, like, WTF, is it fixed or not? I'm guessing the problem was with some electronics on the flight deck, because the "way around the problem" arrived in a small cardboard box to the flight deck.