Is she paying for detention? How is her savings being depleted? Also, I am not aware of airlines having discretion relative to allowing anyone to board a flight without some form of documentation accepted in the Carrier Guide. I imagine if an airline employee let's someone on a plane without proper or verified entrance documentation, it could be that employee paying for the cost of having to fly the person back. In the end, it is the person's responsibility to have their documents in order (not sure where you are going with "paperwork error", elaborate please. I can imagine what it is like for her and her family, but it of her own making. When she left the US without proper re-entry documentation or a valid visa, what was the CBP officer supposed to do? Ideally, she would have been turned around, I don't believe someone from NZ has to have a visa for Canada, so she could have returned to the airport and got on the next flight to Auckland.