Especially if it all got a little nasty I am sure that the Australian Government would be able to figure out who sent the message confidential or not.
I think people are missing the point here. Not only are you entitled to report this stuff, you are obligated to. If another person becomes aware of the breaches or concerns, they also carry this obligation. To report an aviation breach like this in fact reports two breaches.
1. The original matter that was sent to us.
2. The fact that someone is too scared to report this to their employer.