They are allowed now but this is a typical glitch in the online booking tool. It hasn't been updated since the policy was changed last year.

i would just fly back to Auckland on my own dime (around $60) and save the segment for something more valuable.

Okay! Thank you.

I thought if you did that (fly into one airport and out of another in a different city), that it counts as a segment. Hope I'm wrong.When I was fooling around with the AA tool last month, whenever I tried that it counted as a segment. For example, I think when I used to tool to fly into JFK and then out of WAS, a JFK-WAS leg was counted against my total segments even it was overland on my own so I was bumping up against the maximum number of segments.

Yes, but if they fly into Auckland, then, say, drive to Christchurch (counting ferry) and then fly on their own back to Auckland, then Auckland would just be a stopover, and there wouldn't be a surface segment that would count against the 16. When I said they could use that segment elsewhere, I meant later (or earlier) in the trip, for example from DC to Florida, or from Sydney to Melbourne or Brisbane, etc.