Shaykh Dr Zaid Alsalami is an Iraqi born scholar, raised in Australia. He obtained a BA from Al-Mustafa University, Qom, and an MA from the Islamic College in London. He also obtained a PhD from ANU, Canberra. He has written and translated several Islamic texts and also prepared educational videos on Islamic rulings and practices.
There is a clear difference between a civil divorce, of any country, and an Islamic divorce.
It is important that, in addition to pursuing a legal divorce, the couple make sure they obtain an Islamic divorce, observant of all its rulings and in accordance to their sect.
If they only get the legal divorce decree from the civil court, and not an Islamic divorce, it will mean that from a shar'i perspective they are still legitimately husband and wife.
And Allah knows best.