He was investigating the cause of the fire in the Caledonian Rd house, but said it did not appear suspicious.
Initial investigations indicated the fire started in the kitchen, and it appeared from the burn path to have originated from the top of the stove.
The sole occupant of the house, Ian Hayden, said he put some soup on to heat on the stove, left the kitchen and heard an explosion. When he opened the kitchen curtain, the fire erupted.
He fled, but tried to go back to get his dog, which perished in the blaze.
Mr Gibson said once people got out of a fire, they should stay out, not attempt to return, and call for the fire brigade.
The house did not have smoke alarms, and Mr Gibson again emphasised their value.
"This fire engulfed the house very fast. People need to understand the importance of having smoke alarms or making sure they are working to give an early warning so they can get out," he said.
The Oamaru Fire Brigade was called out at 6.59pm on Tuesday, to find the house virtually engulfed by the fire.
Two units and about 15 firefighters controlled the blaze quickly, but were at the house until midnight dampening down hot spots.
After that, the house was checked twice during the night to ensure the fire would not reignite.
