Unlikely to have been a QEA flying-boat, as the Short C/G Class were "borrowed" by the RAAF (33 Sqn) at this stage, and this quick summary from ADF-Serials does not indicate any rescued personnel.
http://www.adf-serials.com.au/resear...lyingboats.pdf
The supply flights from Ceylon to Australia (otherwise named the Flights of the Double Sunrise) would have been carrying urgent passengers/mail/etc and flying at extreme range. Would a captain have endangered his aircraft and crew/pax/cargo for an open sea rescue landing? I think (but my opinion only) unlikely.
No mention of open sea rescues in No11 or No20 Sqn RAAF ORBs (freely available as electronic files on the National Archives Australia website) for August-October 1942. No mention of any USN PatWing 10 involvement in the books I have to hand - but they may have been busy a bit further to the East over Guadalcanal.
One other possibility is RAAF-operated ex-Dutch Do24 flying boats, used as transports.
Trying to be helpful, but probably failing utterly,
...geoff