Investigators determined the man had been “roof surfing,” or riding on top of the 2007 Dodge Caliber as it travelled down the road before it rolled over.
Police say a 35-year-old man, a 40-year-old man and a 27-year-old woman were inside the car when it crashed, but the two men walked away from the scene.
One of the men went to the Vernon RCMP detachment later in the day and was released without being charged.
RCMP and the B.C. Coroners Service are investigating.