One of the last people to see a Canadian couple alive says conditions were too dangerous on the Haast road for anyone to see what had happened.
Joanna Lam and Connor Hayes, both in their mid-20s, went missing after their rented campervan was hit by the slip in bad weather last September. Ms Lam's body was found a week later on the beach near Haast; the body of Mr Hayes has never been recovered.
But Connor Hayes father, Michael Hayes, has been quoted from Ottawa asking why no one notified authorities quickly or crossed the landslide to fetch the stranded couple.
Dayna Buchanan of Haast was on the road that night and gave evidence at the inquest about the landslide.
She says the heavy rain and darkness made it too difficult to check on the couple's campervan, just 20 metres away, without endangering more lives.
Ms Buchanan says the road was covered by a massive pile of trees and dirt leading down the bank and if she had tried to cross she would have fallen.
Coroner David Crerar on Thursday found that the couple died in the slip.
A further inquest into the circumstances surrounding the accident will be held at a later date.