I don't post here very often but always check out this site when the race in on. I'm from Sydney.
Two points I would like to make:
1. Photo of the McDonalds looks very Asian to me, looking at the people in the background and the layout etc. Could be a McDonalds in Kuala Lumpur airport cause I was there for 3 hours in transit a couple of years ago, I didn't recall a McDonalds there at the time but there was a Burger King layout very similar to that in the pic, a lot of the stores were enclosed rather than "open plan" stores. Perth airport is an open layout food court I think, so I wouldn't think its there. The major SE Asian airports are major hubs too so it could just be a transit thing. Hope they are on their way to Australia!
2. Germany speculation could be just Frankfurt airport which is a major hub airport so they could have gone from South America to Africa via Frankfurt.