Booked a ticket aaa-bbb-ccc all on air nz as a UA award. Apparently, the connection in bbb was too short. NZ tells me that they sent a note to UA saying it was under MCT. However, they still allowed the ticketing and did not advise me when printing BP at checkin. Anywho, misconnected since plane didn't arrive until after connection departed due to ATC. I need to push my return back a day since I lost one due to the misconnect. UA says talk to NZ. NZ says their note to UA means it's not their problem and it's UAs.

Two questions:
1)Who's right
2) If it's on UA...My two return options either require booking standard and not saver on a UA ac or booking a 5 connection trip when routing rules allow max of 4. Will they do either? Is one more reasonable to expect?