A British Columbia man found guilty of four sex- and drug-related offences attempted to appeal his convictions earlier this month.

Charles Michael Kavanagh tried to argue that his trial judge was wrong in determining some evidence as credible and reliable.

That judge found Kavanagh guilty of sexual interference, two counts of trafficking drugs (cocaine and methamphetamine) and breach of recognizance tied to an offence dating back to 2016.

Kavanagh's appeal was mostly focused on the allegation of sexual interference. He didn't testify, but his defence team tried to argue against the evidence brought to trial by the victim, who'd been 15 at the time and did not have the legal capacity to consent.

During the trial, the court heard the teenager had been addicted to methamphetamine by the age of 14. The victim, whose identity is covered by a publication ban due to the nature of the case, had dropped out of school, was getting into trouble with the law and had been placed in foster care as his relationship with his family deteriorated.

The teen met Kavanagh, then 57, on Facebook, despite a recognizance unrelated to the case that banned Kavanagh from being with anyone under the age of 16, a decision from the B.C. Court of Appeal reads.

The pair started to spend time together, the court heard, and Kavanagh learned that the teen was under a court order not to use drugs or alcohol, and that he'd spent time in custody and treatment centres.

The teen started to call Kavanagh his "uncle," and their relationship grew to involve Kavanagh supplying to the teen and using with him. He "allowed the complainant to traffic drugs for him," court documents said, found work for the teen and lied to the boy's father and a foster parent that he was an "outreach worker." The trial judge found that Kavanagh was "grooming" the complainant by ingratiating himself into the teen's life.

The incident that resulted in the interference charge occurred in mid-July 2016.

The pair were in Kavanagh's room at a boarding house, smoked meth together, then Kavanagh performed oral sex on the teenager, according to testimony. The teen reported that he passed out, and when he woke up, he saw a blue rubber band around his arm and a syringe stuck in just below his elbow.

The court heard there was "blood drawn," and that the teen's shorts were on the ground and his underwear was pushed down.

Kavanagh was lying next to the teenager in bed and appeared to be sleep, according to evidence presented at the trial.

The teen left, but continued to spend time with Kavanagh, later describing the older man as someone who was "keeping [his] addiction going." The teenager was arrested within a week of the incident, and while in custody disclosed the activity.

The trial judge found the teen's account to be credible, and convicted Kavanagh of the offence of sexual interference.

In his appeal, Kavanagh's legal team argued against the judge's approach to determining credibility. His team argued that a deterioration in the complainant's condition was wrongfully seen as corroboration of his allegation, and pointed out inconsistencies in the teen's statement to police and testimony. His team said the judge "wrongly relied on the absence of evidence of a proved motive to lie as a factor that bolstered the complainant's credibility," and that, among other things, the judge failed to consider that the sexual act may never have occurred – that the complainant was mistaken.

The appeal was heard on June 13, and dismissed just four days later.

The panel of justices said it was not the role of the court to "second-guess the weight assigned to specific items of evidence," and that they were not persuaded that the trial judge committed any reversible errors.