Must have been a peculiar set of circumstanses to cause the crew to elect to make an emergency lob into Brisbane, maybe use the brake hydraulic accumulator to stop and then be unble to clear a main runway.
Much could be explained if the crew were seen to be running briskly away from their Ardvark after stopping.
Why ignore home base, close by, equipped to catch an ailing F-111 by its arrestor hook and bring it to comfortable rest unless continuing time in the air had become an overriding factor.
The whys will be most interesting.