I'm not really sure specifically what the 'Reef on Door' origin story is. It could be something very unique and perhaps related to a local or creative concept that I'm not familiar with.
Not necessarily. Many films labeled as such are only loosely based on real events. 'The Reef' might incorporate some factual aspects but might also have a significant amount of imagination and fictional elements mixed in.
Not necessarily. 'The Reef' could be inspired by true events but might have been heavily fictionalized to make it more engaging or to fit a certain narrative structure.