It says Mark Mitchell, 26, died of a stab wound to the back that penetrated his lung, as well as burns to his entire body. He also suffered a puncture wound to his left forearm.
His girlfriend, 20-year-old Emily Morin, and their housemate Georgia Klap died of smoke inhalation in the blaze, which broke out on their front porch following a Valentine's Day party in February 2013.
Coroner Lyn Blenkinsop classified Mitchell's death as undetermined and did not make any recommendations. No weapons consistent with his injuries were found at the scene.
"The potential exists that the wounds resulted from an altercation with an unknown person or were accidentally caused in some manner when Mr. Mitchell entered the burning porch," she wrote in the report.
Mitchell's parents, Mike and Jori Mitchell, declined to speak by phone and instead sent a brief emailed statement.
"We have no information that we can add to clarify these important matters. For our part, we will continue to mourn the loss of Mark privately," their statement said.
"Whether there need to be or should be further official investigations is something that will have to be decided and pursued by the proper authorities."
Sgt. Jamie McRae of the Victoria Police Department said a "very extensive" investigation concluded there was no foul play and there are no plans to re-open the case.
He said an autopsy revealed the puncture wounds and that an investigation concluded they were not caused by any criminal act.
Officers interviewed everyone who was at the home earlier in the evening and conducted a thorough forensic analysis of the scene, McRae said.
"You can imagine in a chaotic circumstance like that ... you would be doing anything you could do to get out. There's all kinds of possibilities of how these puncture wounds could have occurred.
"When Mr. Mitchell was injured, he may not have realized he was even injured. He was just trying to flee, trying to get out, as most people would."
McRae said one hypothesis is that Mitchell jumped out of his bedroom window to escape the fire and fell onto something on the porch, although officers were unable to prove that happened.
Mitchell lived in the older, wood-framed home with Morin and Klap and a few others. They hosted a party on Feb. 15, 2013, and several guests were smoking on the porch throughout the evening, the report said.
At about 3 a.m., people smelled burning plastic and found that a small fire had started on a couch on the porch where a cigarette had been dropped earlier. They threw the cushions in the yard and poured water on the smouldering couch.
Once it appeared the blaze was fully extinguished, the cushions were placed back on the sofa. At about 4:30 a.m., a resident heard crackling sounds coming from the porch and found it fully engulfed in flames.
The fire department arrived about 10 minutes later and began battling the blaze. Firefighters determined it started in the same area where the earlier small fire was discovered.
Mitchell's badly burned body was later found on the porch, covered with ashes and debris, despite the fact that he was last seen returning to his upstairs bedroom at about 2:30 a.m.
The coroner found that Mitchell was on the porch for the major duration of the fire, but could not determine why he came downstairs or at what time.
Blenkinsop also concluded that a lack of functioning smoke detectors in the home contributed to the fire.
An obituary in the Victoria Times Colonist said Mitchell was a "true Renaissance man" who loved to read and play the guitar and piano. He and Morin both cared deeply about the environment.
"Many people talk about their concerns for the environment — Mark actually got his hands dirty in pursuit of that goal," it said.
"His interest in the land and in farming was shared with his soul mate Emily and together they were on the road to making a difference in the world."
— By Laura Kane in Vancouver