I've been pondering your excellent question today
http://www.theaustralian.com.au/new...k=5b8bc774ec73d08acdb9d0001a90f4c4-1472727571
The thing that makes me think that he's not involved/attention seeking is the claim in the above article that he will make a more detailed statement to police within a month. He didn't have to come forward in the media at all. Why not stay out of it if you had something to hide? The claim that he's holding out information until he wants to talk smacks of a person wanting attention. I can see police saying at end of interview we may want to ask you a few more Qs in the future as we continue our investigation and the puppet master has turned this around to I'm in control and I may, if I feel like it, give police more info in the future. I'm sure police were glad to have him leave. Imagine trying to put a coherent statement together from his rambling.
I can't imagine if the police think he knows where Karen is (alive or not) that they'd be happy waiting a month till he feels like sharing as 1 month could lose vital evidence if KR is deceased (or risk someone moving her). No one outside the family would have connect AR with a different R surname with a family from Avondale height (or gardens as ACA likes to call it!) so he could have stayed out of spotlight altogether, which is what sane guilty person would do (BR & now SR) The rest of the extended family is keeping in the back seat. CR made an early post on one of the Vic police facebook pages (or perhaps it was somewhere else I can't remember) but other than that they've been at pains to stay out of spotlight (aunt P not using her surname until recently), Karen's brother sharing inheritance not wanting to be named.
Also 1 correction to puggles post AR released prison in 2015 not earlier this year, so BR visiting in prison would have been last year, not recently.