"I was beside myself. We were still 20 minutes from there. It was terrifying. Those moments are the worst thing in your life. The last thing you ever want is for something to happen to your kid. I was just thinking, 'Please don't leave until I get there. Just wait for me'."
When she arrived, Lewis was in the back of the ambulance with his brother at his side. He was sedated and his neck was in a brace. He was rushed to Auckland Hospital, but sent home a few hours later.
Ms Prime said his body had "shut down" with the shock of the impact to his neck and head, meaning he could not move. Doctors told her it was the body's way of protecting his spine and neck and giving it a chance to heal.
"He started to get movement back in his body at about 10pm. I was thinking, 'Thank goodness'," she said.
Lewis spent three weeks with his neck in a brace and, while he has been told to be careful, he's back playing sport.
"It's the first time he's had a major injury. You see a lot of things like this on the television show but you never think it will happen to your son."
Ms Prime was thankful Lewis' teachers acted quickly, preventing further or more serious injury.
She also wanted to thank St John Ambulance and the Auckland Westpac Rescue Helicopter crews.
"I will never stop singing their praises. They were just so great. I really applaud what they do. I was so terrified and they were all so calm. They were really wonderful right through to when they left us at the hospital."
Lewis Arthur's rescue will screen on the season finale of TV2's Code: 1 tomorrow at 8pm