Aussies and Brits have distinctly different accents, but to many American ears, they sound very similar. Same with the Kiwis.
Yup... was going o mention that, but you beat me to it. A few years overseas will cure anyone of that mistake ;)
When I first came to Japan, they all sounded alike... had a few acquaintances from the 3 (UK, Australia, and NZ)... first roomate was from NZ... Can now hear a pretty big difference between all 3.