The British Empires claim of "extraterritoriality" was one of the causes of the Opium wars in China in the nineteenth century. This was the claim by the British that their subjects should be covered by British justice not Chinese justice even when on Chinese soil.
The concept seems rude, arrogant and so completely out of touch with the post World War II environment that has seen the end of empire and the acknowledgement of the rights of citizens to run their own countries.
Except of course if you are the Tele and the subject matter is an Australian convicted of drug smuggling. In today's Tele Tracey Spicer makes a case that Schapelle Corby should not "die in Bali".
However, it seems that the core basis for the claim is that "A crime which would have garnered a short period of humane treatment in an Australian jail has left her rotting in a foreign hell hole." This seems to be the thrust of the argument, and is a construction of one of three possible underlying beliefs;
1. Australia is culturally superior to Indonesia and therefore our laws ae more appropriate than theirs.
2. If two laws could apply, only the most lenient should, or
3. The laws that apply to a citizens home country should apply no matter where the person commits the offence.
The reasoning can't be 2, because then if an Iranian citizen had conducted the fatwah against Salmon Rushdie in Australia, there would be no penalty because the murder would ot have been a crime in Iran.
The reasoning can't be 3, because then if a Saudi citizen was found guilty of theft in Australia they should have their hand cut off.
Therefore the claim is the cutlturally arrogant option 1.
Now Spicer might defend herself, and argue that really all she is trying to argue for is the right for prisoners to serve their gaol terms in their home countries because this would be better for them psychologically. That is a claim that has some merit, but it is a claim that should apply to all criminals bilaterally by treaty. Those treaties need to reflect that the purpose of the exchange is not to provide leniency on the sentence but to facilitate the incarceration.
But that case would have nothing at all to do with the nature f the crime and how it would have been treated differently under Australian law.
That said, I do believe it is acceptable for citizens of one country to "moralise" over the laws of another. Howevr, to be effective this would really be best conducted on a platform of a worked through secular moral code. I'm not holding my breath for the Tele to do that!