Arm out the window - I agree, letting untrained pilots loose by night is not appropriate. That doesn't change the rules though, and the rules do not require you to be able to discern a horizon to be VFR (by night or day).
NZ CAA Rules Part 91 Subpart D — Visual Flight Rules,
91.301 "VFR meteorological minima" refers. Unsure of the Oz equivalent.
(edited sp)