Kārearea nest preparation?

Late September we detected kārerea (NZ falcon) activity around a hollow under a decaying log, it appeared nest preparation was in progress. We roped off the site as it was close to a track used by Brook Waimārama Sanctuary staff and volunteers, too close for the comfort of the birds and humans. I'd been checking it out whenever I passed (about once per week) for signs of activity. The last activity I saw was 7th October. We'd been considering whether the rope could be safely removed as the site appeared inactive (cobwebs across the hollow entrance, no fresh droppings or regurgitation pellets). Until today.

I walked up the spur, over the rope, and saw no eggs (or anything else) in the potential nest hollow. I was standing right next to the hollow (about 2m away), I'd been there for a few seconds when a blood-curdling screech from above shook me to my core. I looked up, and a female kārearea was in the air about 5-6m above me, wings flapping and shrieking. She was making herself look and sound as intimidating as possible (although no attempt was made to attack). She was trying to scare me away. It worked. I beat a hasty retreat to a spot about 10m away.

The male then turned up, and on the other side of the log (about a metre from the 'nest' hollow) I saw them feeding on the carcass of a decent-sized bird. It appeared to be perhaps a tūī or California quail. It appeared they'd stashed the carcass there, and perhaps that was the reason for the aggression, they may have thought I was going to raid their food supply.

Anyway, once I was 10m away (outside the rope) the pair of them seemed unconcerned by my presence and ignored me thereafter, so I took some photos. The only appearance of the female in these photos is the one where she is feeding while the male watches from his perch. The other photos are the male.