They did have proof of onward travel, since they had confirmed reservations on a cruise departing Sydney and confirmed reservations on a BA flight from BKK (which EDI check-in staff could also see). And actually it transpired that they also had onward travel from the country because a relative had already made their reservations for the return TT - but they weren't carrying details of it with them, since they didn't need to! (yeah, I know ) And in fairness, I hadn't spotted any problem with them not having it, so I can't shout at them for being Too Stupid To Travel Unassisted (tm).

It appears that the problem came not with NZ immigration staff, but with QF check-in staff at SYD where they had to go and check in for the SYD-AKL leg (despite being all on one ticket, they had not been able to check in for this leg in EDI). QF did the eligibility check that airlines should do and nearly refused to let them travel - having Air New Zealand fax over their confirmed reservation for AKL-SYD to connect back to the cruise actually solved the problem in the end, but took some co-ordination. OTOH, they were flying in J, so the airline on this occasion did the running around to help them get it sorted. If worst came to worse, they probably could have bought a oneway there and then, but I suspect my mother's ability to radiate confused charm might have helped get it sorted.... But anyway, it gave them a wee adventure to tell to people about how NZ nearly refused to admit them on their big world adventure!