3 Greens I agree.
Beyond any doubt he should have politely listened, had a look, and reassured the passenger. The Kiwi Captain handled the situation very badly. Or so it would appear from what we are able to read here.
However, I do find it interesting that kkiwi flew on the service. With an "idiot" pilot and a crack that "started about halfway back and continued to the outside edge in a zig-zag pattern", I would have declined to fly.
If I was convinced of my knowledge, and kkiwi must have been convinced as he publicly abused the Captain, why fly?