"But at lunch break I decided to come out and bring the car closer to the church.
"After I'd parked it, I stood outside for a while talking to someone I knew. We were standing there for a long time before I walked back to church."
Less than 10 minutes later, a member approached Mr Naisau to let him know that his vehicle had been damaged.
"We went out to look ... I couldn't believe it. I was standing there not 10 minutes before - that could've been me underneath that branch."
Mr Naisau, a pastor of the same church based in Lautoka in Fiji, said he had no idea how he was going to help his relatives, who loaned them the car.
The vehicle was not insured.
"I was so disappointed in myself because it was a borrowed car. It's not nice having to call the owner of the car to tell them it's been damaged."
But as the conference continued into the evening, news spread of the incident and a spontaneous call was made to help Mr and Mrs Naisau. Within hours $8500 was raised.
Auckland C3 Church pastor Dean Rush said it was very much a "spur of the moment thing".
"We were nearing the end of the night and somebody had been talking about a message of helping others," he said. "I just stood up and said: 'We've got an opportunity to help someone in need right now. They've possibly got a big debt now and we can help them'.
"We just played a song and people started coming up offering what money they could."
The church is now working with Mr and Mrs Naisau's relatives to buy a new vehicle for their family.
Mr Naisau - the leader of about 120 people at his church in Fiji - said: "I just stood there and cried. The whole day I had been so worried and here were all these people helping us.
"We always preach to people to be generous and loving and to give to others. That day, they were helping me."