In this respect, the case illustrates the difference between the two leaders. Collins indicates she would have taken the unilateral approach for the safety of New Zealanders, at the risk of defying international conventions.
Ardern has adhered to the conventions while setting law change in motion. Under these laws, we hope for certainty that the offending by Samsudeen prior to Friday's attack would be enough to detain such a person.
Whether Collins' strategy would have been effective, particularly given the lengthy deliberations of the courts already undertaken into Samsudeen's case, we won't know. Seven people have been wounded, four grievously, and their deranged assailant is dead.
Ardern is right to seek answers on what to do with a person who fraudulently gains refugee status as a protected person and then becomes a threat to national security. But as part of our commitment to human rights and human dignity, we should not bend to the will of terror and send people to their death or torture, the gravest of human rights abuse.
Some have asked why Samsudeen was prevented from flying on a one-way ticket to Singapore, en route - he claimed - for Syria. The answer is, New Zealand is not the kind of nation that wilfully sets maniacal threats on others.
Likewise, an act of terror should not derail our duty as a global citizen to our displaced co-inhabitants; more than 82 million of them last year, according to the UN Refugee Agency.
Climate change is threatening more nations who are unable to support themselves already and the refugee tide is predicted to worsen. "Climate change is driving displacement and increasing the vulnerability of those already forced to flee," the UN Refugee Agency reports. "The dynamics of poverty, food insecurity, climate change, conflict and displacement are increasingly interconnected and mutually reinforcing, driving more and more people to search for safety and security."
Most refugees land gladly in Aotearoa, welcoming sanctuary and hospitality. But it's a sad reality that some arrive disturbed and hardened. The refugee regime can also be exploited by less than worthy candidates.
None of this, nor the events at LynMall, should change how we view refugees. However, while seeking to better protect ourselves, we should remember how harsh some parts of the world are and how fortunate we are.