Looks like you did some research. I was aware of the general law around my neck of the woods but still checked before I posted and came across the same link you found. To confirm further, checked some links relevant to Victoria.
The premise is, that if you are in a public place it's not private and you can be expected to be seen. Under our stalking & family violence laws, your rights might be infringed and for good reason. Generally though, for good, decent, honest, law-abiding individuals setting up security cameras, even covertly, is not a crime.