I spoke to a copper at Cronulla who was a good guy, he listened, understood and told me what to do.
Then I spoke to Highway Patrol at Miranda (at the first guys suggestion). The woman there was a bit hard to get through to, seemed to have trouble understanding the concept of freedom of association but I kept at her and she finally got it and relaxed a little.
Niether of them thought that our visitors from Friday handled themselves particularly well but they did explain some of their actions which was helpful.
So all in all, message appears to have been received; as long as we tell them in advance who we are, where we are going and what time the worst they will do is come and say hello.