WINNIPEG -- A Winnipeg musician who left his mother on the floor after a fall, was back in court Tuesday as the Crown appeals his sentence.

Last July, Ron Siwicki was sentenced to three months in jail for criminal negligence causing the death of his mother, Elizabeth Siwicki.

One month was subtracted for the time served in custody before the trial.

Elizabeth, 89, fell out of her bed in November 2014 and died several weeks later due to bed sores so severe, they went down to her bones.

In the notice of appeal, the Crown said Court of Queen's Bench Justice Colleen Suche made an error in her assessment of aggravating and mitigating factors and passed on an unfit sentence.

In her submissions to the Court of Appeal, Crown lawyer Rekha Malaviya said "this did occur over a prolonged period of time and this increases his moral culpability." She argued that a three month-sentence is not appropriate to denunciate the crime.

The Crown is asking for a 36-month sentence less time served.

But Siwicki's lawyer, Michael Cook, told the court, "I ask you to dismiss the Crown's appeal and allow the sentence to stand." 

Cook says the defence had sought a sentence of probation for Siwicki, but didn't receive it from the trial judge. He says they were satisfied that it was a "fair sentence." 

"It's not a case of malice or indifference. He made a mistake. There's an awful lot of good in this man."

The appeals court judges have reserved their decision.