The September 26, 2016 event is highly significant. Pete has not seen previous reports about it. The release of perhaps confidential details about the event is likely to have come from the Japanese Government to Sankei News . Pete thinks the Japanese Government strategy behind such a release might be to encourage the Australian Government/military to be more active in patrols and Freedom of Navigation Operations (FONOPs) in the South China Sea against China's claims.
The US Government may also have been involved in briefing Sankei News because the US would also want increased Australian patrol/FONOPs activity. US officials were also present at the mid December 2016 mentioned above.