Roch Bernier told a news conference Thursday that coroner Cyrille Delage unjustly targeted the managers and staff at Residence du Havre, in particular the night watchman, Bruno Belanger.
Delage published a report in mid-February citing a lack of training and emergency plan as some of the reasons so many people died in January 2014 in L'Isle-Verte.
Bernier pointed the finger at "stakeholders" in fire prevention he says didn't explicitly tell him what to do in the event of an emergency.
Bernier said evacuation procedures would have been different had he and his co-owner been better informed.
He also said staff, including Belanger, did everything they could to save people that night.
Delage questioned the credibility of Belanger's testimony at his inquiry and suggested he didn't do anything to save residents.
"Mr. Belanger did not lie and Mr. Belanger did his work as he should have, given the circumstances," Bernier said.
The co-owner also agrees with Belanger that the fire started on the second floor and not in the kitchen, as suggested by a Quebec provincial police probe.
Investigators traced the fire to the ground floor but weren't able to establish the exact cause.
No one has been charged criminally in the case.
Bernier said he's awaiting the results of a private investigation into the blaze and is considering civil suits over the construction and renovation of the home.