Six years after Dustin Paxton dropped off his roommate at a Regina hospital weighing just 87 pounds, disfigured from daily beatings and with permanent brain damage, the 36-year-old is appealing his convictions of sexual and aggravated assault.

Paxton was deemed a dangerous offender and handed an indeterminate sentence in 2012 after being convicted of assaulting his victim and business partner over an 18-month period.

During the trial, the victim testified he had been beaten by Paxton daily since Halloween night 2008. The pair moved from Winnipeg to Calgary to start a moving business together.

On Wednesday, defence lawyers Alias Sanders and Andrea Serink argued before a panel of three Alberta Court of Appeal judges that his conviction should be overturned because of errors made by the trial judge.​

The man — whose identity is protected by a publication ban because he was the victim of sexual assault — was emaciated, disfigured and has permanent brain damage.

Charter rights violated, argues lawyer

Paxton's grounds of appeal argue Justice Sheilah Martin demonstrated bias throughout the trial, and his charter rights were violated because expert testimony that described the victim's testimony as unreliable was excluded.

The trial judge should not have found that Paxton was guilty of sexual assault because his roommate's testimony was vague and based on "perceptions" not detailed memories, argued Sanders who is asking for an outright acquittal on that charge.

Dustin Paxton's victim weighed just 87 pounds when he was dropped off at hospital, down from his normal 200 to 250 pounds. (CBC )

"We don't have ... that the accused threatens by act or gesture that this has to be done," said Sanders. "What's lacking in this case is evidence from the complainant of acts and gestures of what leads to the sexual conduct."

"The [trial] judge made a finding based on the perceptions of the complainant," argued Sanders. "We have nothing with which to measure [the victim's] perception."

But Justice Bruce McDonald, one of the three judges on the panel, voiced doubts about defence's argument.

"It doesn't surprise me he suppressed these very degrading events," said McDonald. "I don't find it all that strange that someone, particularly someone who suffered this brain injury, would be vague on those details."

Paxton had 'total dominance' over victim

In his arguments, prosecutor Dave Labrenz said Paxton had "total domination" over his victim and subjected him to daily violence.

"There's no way that Mr. Paxton could have an honest belief ... that there was any consent."

Though Sanders' submissions focused on the sexual assault conviction, she also argued that the aggravated assault conviction was also tainted by unreliable witnesses.

Another issue touched on by defence was with disclosure. At one point in the trial, it was discovered that the victim was posting details of the case to Facebook. Paxton's lawyers argued they should have been sent screen grabs of the posts by any number of people who were Facebook friends with the complainant, including two police detectives.

Trial judge did 'superhuman job' says Crown

Sanders also argued Martin erred by not ruling Paxton's charter rights were breached by late disclosure of evidence and other issues, and should have resulted in a stay of proceedings, ending the prosecution mid-trial.

Appellate prosecutors Jolaine Antonio and Dave Labrenz argue the stay application was frivolous and should have been dismissed without even hearing arguments from the defence.

"I am embarrassed to be critical of this trial judge after the superhuman job she did," said Antonio when addressing the stay application during the trial.

"If the two sets of reasons given by the judge are insufficient then every trial judge in Alberta might as well give up."

The judges could side with the prosecutors and Paxton's convictions would be upheld. If it sides with the defence, either a new trial will be ordered, or Paxton would be acquitted on one or both of the charges.

The panel has reserved its decision.

Paxton is also appealing his dangerous offender designation and indeterminate sentence — those arguments will be heard at a later date.