Evidence of the unfortunate incident emerged in the trial of Drew Francis Thompson, 28, who is accused of arming himself with a gun, hiding in his former lover's apartment, and unlawfully confining her for three hours.

Thompson began giving evidence on Thursday afternoon, saying the woman changed when she came back from an overseas internship with the World Health Organisation.

He still wanted to be with her and met her at Dickson shops, where she spoke harshly to him.

Thompson said she called him "simple" and a "door mat", who she had used as a dating experiment.

"She said there'd be no chance of it happening again," he said.

The Crown allege he took a gun and hid behind a door in her spare room to show her what it felt like to break someone's trust.

Three hours later, after convincing the man to leave, the woman said she went to police, who executed a search warrant on Thompson's home.

An officer involved in the raid told the court on Thursday that a police dog had bitten a constable on the bottom while they were at the home.

That prompted laughter in the court and defence barrister Jack Pappas asked: "Did it survive?"

"Yes. Yes it did," the officer responded.

Mr Pappas also continued his cross-examination of the complainant on Thursday morning.

He accused her of becoming fed up with Thompson, who had not been getting her hints that the relationship was over.

Mr Pappas accused her of inventing an appalling lie to police.

He suggested to her that she had all the raw material from her knowledge of Thompson to create an elaborate lie.

She responded: "It's not a lie. I don't know what to say to that Mr Pappas."

Mr Pappas said the gun in evidence was designed for a right-handed person, while Thompson was left-handed.

She said she had no idea he was left-handed.

Mr Pappas also asked her why she didn't call triple-0 as soon as Thompson left her apartment, instead of going outside and driving to a police station, despite fearing he might come back and kill her.

She said she feared he would come back and break back into her apartment.

The woman agreed she had offered Thompson chocolates and lollies while he was in the home, allowed him to put his hand on her hand and leg, and was concerned about being a good hostess.

The trial continues in the ACT Supreme Court before Acting Justice David Robinson.

Thompson is expected to continue giving his evidence.