Singh said he realised when he arrived she was "already tipsy". He tried to ignore her by watching television and playing computer games.
He said Sale began swearing and became aggressive, so he left. The last time he saw her was 9pm.
"That was the other side to Amanda," he said.
He answered a call from an hour later asking if he had seen her glasses as she was going for a drive. Given his own assessment of her state, he said he didn't believe she would drive.
"I thought it would be alright. I wanted to give her some space...she gets really drunk...I was thinking she's not going to drive anyway," he said.
Singh told the court he too suffered from bad eyesight.
"We can't see without glasses. We are really bad," he said.
Sale then rang him five times in quick succession shortly before she crashed, calls he didn't answer.
Her speed was estimated at between 135-150km/h when her car crashed into a bank. It was unknown whether she was wearing a seatbelt and she was thrown from the car onto the road.
As her body lay on the road, it was run over by the truck shortly after.
After feeling the impact, the truck driver reacted and investigations showed tyre marks leading away from the site.
James Bennet from the Serious Crash Unit said studies showed a person darkly dressed at night standing up was hard to see, but lying down at night was almost impossible.
Singh said Sale was wearing a dark-grey hooded sweatshirt and black full-length trousers when he last saw her.
Damage to the truck showed Sale had been lying down when she was struck.
Serious crash investigator Les Maddaford said tyre pressures on Sale's car were checked after the accident and showed one tyre was a third over-inflated and another tyre under-inflated by the same amount, which made driving at speed "undesirable".
The car had passed a recent wheel alignment test.
Coroner Scott said there were three possible causes of Sale's death - the impact of the car hitting the bank, the impact of her hitting the road, and the result of being run over by the truck.
He said it was unrealistic and unfair to have expected the truck driver to have seen Sale on the road.
Sale's family told the hearing they did not hold the truck driver responsible in any way for her death.
The Coroner's final decision was expected to be released in 14 days.