I think the hypothesis of billabong drowning can also be rejected.  This study found average depths (greatest depths) at 1-2 meters.

https://www.dcceew.gov.au/sites/default/files/documents/rr2.pdf

Quote

The four billabongs are shallow (1-2 m deep), with shelving banks and clay or silt bottoms with accumulations of organic matter. There is little bankside vegetation around these billabongs, this probably having been destroyed by buffalo. The waters are normally very turbid, particularly during the dry season.

What are the odds that you could jump far enough to clear the shelving banks and land in a section deep enough to drown you?  And if you were trying to deliberately drown yourself to evade the troopers, you would surely fail, as they would have little difficulty stepping in there and yanking you out before you could succeed.  Also, the laryngospasm reflex would prevent you from actually taking significant amounts of water into your lungs - most drownings are actually caused by asphyxiation as the laryngospasm has closed the airway.  Water does not enter the lungs in volume until after death.  

1 hour ago, mistermack said:

They do give your hypothesis credit as a second benefit though, but if that's the case, life must be murder in those baggy shorts.  

It has always been my assumption that life in Australia is murder.  How else to explain an area the size of the United States with only one fourteenth its population?  (if this were a serious comment, that could be a whole other thread, I guess.)

8 minutes ago, TheVat said:

It has always been my assumption that life in Australia is murder.  How else to explain an area the size of the United States with only one fourteenth its population?  (if this were a serious comment, that could be a whole other thread, I guess.)

Hello! They were sending them to jail!

And then - do what you want - at least here..

If I send you to a space station on the moon or Mars and then release you, you will be in the same situation as they were 200 years ago....

 

 

40 minutes ago, TheVat said:

How else to explain an area the size of the United States with only one fourteenth its population? 

A big part of the reason is that it was about six thousand km from Liverpool to New York, but about twenty five thousand to Sydney. Although the Suez ditch shortened that a bit. That really was no joke, in a little sailing ship.