For the guys heading over to flight screening in the coming months, all the information you need is in this thread somewhere. You can't prepare for some of the things they throw at you and that's just PSA's way of determining whether or not you've got what it takes. I personally believe prior flying experience will help the flying side of things; I had ten hours on ultra-lights logged in the last twelve months and didn't do too badly with the flying but there does come a point when you're left to your natural abilities in the air.
As for the fast jet pilots doing what they're trained to do, we had a speech on why the Army and the Navy offer a better opportunity to "use your wings" than the RAAF does and the point the Lieutenant made was the fact that Australian fighter pilots hadn't been deployed to fight other aircraft since the Korean war and are more or less stuck to training the skills and abilities they may never get to use in a hostile environment.