The defence in a two-week-long civil trial against the territorial government called its first witness in Yukon Supreme Court on Wednesday after the plaintiff's council concluded its case.

A 70-year-old former principal of a local elementary school, who is one of the defendants in the case, testified in the afternoon.

The man, who cannot be named under a court-ordered publication ban, testified he never sexually assaulted the 34-year-old male plaintiff in the case.

The incidents of sexual abuse are alleged to have occurred in 1979, when the plaintiff was five years old.

The man said he remembered the plaintiff as a "small kindergarten student" who had a "bowel problem."

The man said he believed this was a medical problem and he was not aware of any other issues nor difficulties having to do with the boy.

Regarding the plaintiff's allegations of sexual abuse, the man said he has "no comment."

"Those are (the plaintiff's) words. I never touched (the plaintiff's) penis or genital area. I never touched him over or under his pants.

"I have never rubbed my pelvic area against (the plaintiff). I have never made (the plaintiff) touch my genitals," he said when questioned by his lawyer, Keith Parrkari.

Parrkari said in his opening statement he would prove the "impossibility of abuse happening in a room or a closet as described by (the plaintiff)."

Parrkari entered as evidence five blueprints of the school where the alleged abuse took place.

The plaintiff's lawyer, Dan Shier, objected to the blueprints' use.

"Their prejudicial value may be quite extreme," he said.

Justice John Richard overruled the objection and the man was permitted to view the blueprints during his testimony.

The man said his office from 30 years ago contained a desk, a circle of chairs, a rocking chair, a long table, a filing cabinet and a stack of cushions for children to sit on. There was no closet, he testified.

"I was there for all children," the man said. "I tried my utmost to be of service to them. I felt good about my service. I did as much as I could do to the best of my abilities."

Shier's cross-examination of the man was scheduled for this morning.

The plaintiff's final witness was Robert Colby, a clinical psychologist who has expertise in childhood sexual abuse.

Colby performed an assessment of the plaintiff prior to the trial, court heard. His diagnosis was that the plaintiff suffers from post-traumatic stress disorder, with features of anti-social personality disorder.

"In this case, we're dealing with an issue of self-hatred. (The plaintiff's) anger is sometimes turned inward and he wants to cry and hurt himself.

"Other times, it's turned outward and he wants to get revenge on (the former school principal)," Colby said on the stand.

The plaintiff testified last week he has been in the habit of burning himself and cutting himself for many years.

Colby said people who practise self-mutilation do so "just to know they're alive. The punishment is confirmation that they're there."

Colby said the plaintiff's level of functioning is at the Grades 6-8 range.

During cross-examination, defence lawyer John Henderson said the plaintiff's test results indicate he was either exaggerating his symptoms, or has "such a high level of psychopathology that he requires hospitalization."

Colby said test subjects sometimes "amplify their symptoms" as a way of crying out for help.

"They just want someone to know how absolutely awful they feel," said Colby.

But Colby said the plaintiff is a "functional human being."