"He could have relied on me to point out the deficiencies and problems in the Crown's evidence. But he wants to give evidence and he wants to give his side of the story, a story that proves he is not guilty," Mr Calver told the court.
Mr Calver said that in many alleged sexual crime cases there were no witnesses but simply a "he said, she said" situation.
The court has already heard from the other paramedics who were present in the ambulance at the times of the alleged crimes.
He said the jury would now hear from all those who were there.
When he took the stand, King was asked by Mr Calver if there was any truth to the allegations against him, he said "definitely not".
He recalled the incident involving a then 15-year-old girl on July 24, 2013.
He was treating the girl and took her away from the scene of an incident.
He contacted St John's communications via his cellphone before preparing to travel to the Waipukurau Medical Centre.
The teen requested she be accompanied by a friend or family member in the ambulance, but those present declined. "[She] didn't trust me ... she didn't like being transported unaccompanied."
"I told her it may be necessary to stop in Waipawa depending on how she was feeling and that I may need a second set of vitals."
King said he had left his clipboard and cell phone in the back of the ambulance with the patient as he began his journey.
"I left it where I was sitting. That way I knew I had good communication front and back."
King said he stopped the ambulance after the teenager said she was still in pain, because he was concerned about her head injury, and because he wanted to "provide due medical care".
He said he performed another medical exam, while also administering the pain relief gas Entonox.
King said the claims made by the Crown that the 10 minutes he spent parked on the side of the road were too long, were unreasonable because it was dependent on the patient.
"It depends in the patient, it depends on the gear you are using, so the times can vary."
He said he never inappropriately touched the teen, or recorded intimate videos of her, while parked on the side of the road, as the Crown alleges.
After arriving at the medical centre he said the teen "sat up on the side of the bed and started screaming 'let me out, let me out'."
He recalled picking up his cell phone before leaving the ambulance but had no "conscious recollection of deleting" the alleged intimate images.
"I wish I really hadn't deleted anything from the camera and then we wouldn't be talking about this now," King said.
As part of the Crown's evidence an expert witness described finding "digital footprints" on King's cellphone showing the creation of two videos during the ambulance's journey.
King said in response to the allegations against the teen: "I acted with full professionalism and endeavoured to give her the best possible treatment I could."
The trial continues.
