inbound and outbound flights all via HK

The requirement for a 72 hour visa is that passengers must have proof of a flight to a third country. If the flight into Beijing from New Zealand (USA citizen) is a connection flight (in Hong Kong with a 1.5 hour layover) and the passenger flies to Hong Kong from Beijing within 72 hours, does it matter that the flight incoming was technically from Hong Kong? or do they accept the origination point of New Zealand?