They spoke to NZ immigration as well, who seemed to be aware of the problem so this may not be unique and there is a bug in the process. I agree that the story seems odd, Clearly there was a back end review that revoked the visa. One other potential thought... we were also in NZ at the time, and had applied through the app which seemed to be what NZ immigration was suggesting and also was a bit cheaper. They applied online (web link) vs the app, and there could be a difference in the logic. I know the people, so just taking the story from the horse's mouth.