How?
Fuck knows...

So, we get off the plane and pass through the electronic passport scanning...
On the other side there is a monitor that says the Sydney flight luggage is on carousel 6. We are standing at carousel 1...
So we walk down past carousel 2, past carousel 3, past carousel 4, past carousel 5 and between us and carousel 6 is a mahoosive customs wumman who says, "JOIN THAT LINE". So we join the line...
Immigration is simple, couple of questions then we are through... we have to put our carry-on bags through the X-Ray machine, get sniffed by the drugs dog and then woo-hooo, we are, um in the arrivals hall, being met but with no luggage...
So, we can't go back into the customs hall, we are directed outside and to the handling agent... which is closed... Press (repeatedly) the 24 hour call bell but nothing, the plane was late arriving so we are like 2:30am in the dark and nothing... I head back to the terminal and find the tallest security officer you have ever seen in your life!
The security officer takes me back outside and waves his pass in front of a scanner which miraculously produces an employee who then goes off to find our luggage - the automatic door closes and we are trapped in a 2m x 2m 'waiting room' waiting for numpty to find our luggage and take it to security where it was all opened and inspected... God knows what time we got to bed...