Original text from WS Journal:

North Korea reported its first death from a Covid-19 outbreak that it said for the first time had rapidly spread throughout the country.

我的理解：

it = North Korea

that had rapidly spread throughout the country 是定语从句，修饰前面的 a Covid-19 outbreak

it said for the first time

是否可以理解为插入语？改为：

North Korea said for the first time that a Covid-19 outbreak had rapidly spread throughout the country. 

请帮忙确认是否理解正确，谢谢！