Dr Buchanan said if any of the 30 or 40 people suspected of being local extremists acted on the list, they'd end up attacking the New Zealand target's father, since the targeted man was now living abroad.
"So now imagine if one of these guys attacks the house or hurts the father. That's the point -- they want to sow fear and panic."
Such an attack would cause some members of the public and more politicians to start questioning the current Kiwi deployment in Iraq, he said.
"The point is to sow fear, saying, 'We can touch you now that we have self-radicalised people in your country'. So let's just hope the SIS [Security Intelligence Service] and the cops are onto it," Dr Buchanan said.
Isis operatives or sympathisers didn't care how accurate or current the information was, he said.
"They just want to send a message to the New Zealand public that they can be touched in a bad way."
Some tech commentators have cast suspicion on the kill list.
"This is at least the third time this year that Isis has claimed to have hacked into government servers and extract the personal details of United States officials. 'Hack' is a misleading verb, though, because in each of those instances, the terrorists didn't exactly compromise America's information security fortress," Gizmodo reported today.
"Either the 'hacked' information was already public, or apparently completely fabricated," Gizmodo added.
Deakin University information security researcher Prof Matt Warren also raised questions about the kill lists' authenticity.
The list was "a non-government subscription list" and "not such a great victory" for Isis, he wrote on Twitter.
Prof Warren said the leaked passwords seemed fake and did not conform to password naming conventions.
Isis has sparked more disgust in recent days with new atrocities and the emergence of details on its theology of mass rape.
Even the Taleban condemned an execution where Isis forced prisoners to kneel on landmines, blowing them up simultaneously.
The Taleban this week called the execution a "heinous" and "un-Islamic act" where innocent civilians were martyred after being charged with apostasy.
"This offence and other such brutal actions by a few irresponsible ignorant individuals under the guise of Islam and Muslims are intolerable," the group said.
The New York Times yesterday reported on a "bureaucracy" dedicated to perpetuating sexual slavery and the persecution of women from religious groups Isis disagreed with.
"The systematic rape of women and girls from the Yazidi religious minority has become deeply enmeshed in the organisation and the radical theology of the Islamic State in the year since the group announced it was reviving slavery as an institution," the New York Times reported.
Isis had "developed a detailed bureaucracy of sex slavery", the newspaper said.
"And the practice has become an established recruiting tool to lure men from deeply conservative Muslim societies, where casual sex is taboo and dating is forbidden."
Meanwhile, the Guardian today said Kurdish forces fighting Isis in northern Iraq were reportedly attacked with chemical weapons.
"We have indications that there was an attack with chemical weapons," a German defence ministry spokesman told the Guardian, saying "many" Peshmerga fighters were now suffering from respiratory irritation.