PA28181
The club you are probably talking about is the Marlborough Aero Club based at NZOM. Take a look at this link and you will see they're open till 17:00 every day.
Contact/Find Us | The Marlborough Aero Club
Knowing some of the people involved at the club I'd guess that if a tourist turned up for a flight close to closing time they'd happily do it.
Considering the closing time for pubs in NZ is 22:00 hrs I'd say you were either not all that thirsty or didn't try very hard. I've traveled down that way and had no problems getting a beer at the time you mention.
Me thinks you might be prone to exaggeration.