Alphacentauri - a nice point and you are quite correct, although I might say that IMO the OAR has paralysis and a lack of analysis! The last review I could find was the 2017 supplementary I referred to above, yet the Minister states that they will respond quickly to any new issues that arise! I think we are in wild agreement, although I believe the evidence is in, we do not need any more analysis.
TIEW - I fail to follow your logic in terms of sharing a CA/GRS.
Sure Ballina Shire Council "volunteered" to install the CA/GRS but it operates on the common CTAF so it cannot ignore any communications on that frequency. I could understand the CA/GRO not getting involved with traffic advertising it is in or near LIS because he/she does not have the full picture. (For instance he/she cannot hear aircraft taxiing at LIS) There is still however a duty of care, If the CA/GRO thinks he/she has information that the pilot(s) should know he/she cannot withhold it due to a perception that it is not their business.
In this case though, one of the aircraft was heading for BNA on a track known to the CA/GRO and one was east of LIS heading for EVD. A simple chinagraph line on a map will indicate that the tracks will cross. The idea that traffic is not passed because one aircraft was broadcasting to LIS traffic instead of BNA traffic, has me foxed, I do not follow your logic.