Gunn sent a text message to his flatmate’s father, saying: “The chicken is dead, mate. A fox or something got it. I’m not sure how to put it. Sorry.”
In another text he wrote: “I’ve got it under wraps until someone gets home to get rid of the carcass.”
In a subsequent phone call, Gunn claimed an Indigenous person broke in and he fatally stabbed them.
The court heard he said that because he was ashamed he slept with her.
When paramedics arrived, Ms Dann was still alive but she died in hospital hours later.
In his victim impact statement, Ms Dann’s father referred to violence against women and said his daughter “didn’t deserve to die in this way”.
“The laughter, hugs, guidance and the opportunity to say, ‘I love you’, are gone forever. Our family is forever broken,” he said.
“My daughter’s life was cut short, and was robbed of caring and nurturing her baby boy.”
Ms Dann’s mother said: “No one deserves death from a hideous crime. That haunts me and my family forever.”
Justice Joseph McGrath described the family’s grief as extraordinary.
He acknowledged Gunn’s actions were in response to Ms Dann’s outburst, but said he used excessive self-defence.
Justice McGrath also noted Gunn failed to render assistance immediately, but accepted he panicked because he thought he had killed her and was now remorseful.
In a letter to the court, Gunn said it was never his intention in life to cause so much chaos, grief and loss.
Gunn, who pleaded guilty to manslaughter, will be eligible for parole after serving six years behind bars.