"I was very scared. I abused the hell out of my father.''
Raymond jnr was in a moderate condition when taken to hospital by ambulance. He was discharged later that night.
Hospital staff all had the same message for Mr Kapene and wife Melissa Kapene - they were incredibly fortunate their son was not more badly injured, he said.
"We are just lucky the trailer didn't have a load on it. So lucky.''
Mr Kapene said he had since become more protective of his son and warned other rural parents to be more aware of potential dangers.
"It was stupid really. A lot of farmers do it and have their kids sitting on the tailgate and have a trailer behind them.
"They take it for granted. The country, the way people do things. We like to let our kids run around and do what they will but as we learned it can be just-like-that. Like the doctors and nurses said, he's lucky to be here.''
Raymond jnr was back at home yesterday, playing with 10-year-old sister Ngahina and pointing out the exact spot where he fell.
Mr Kapene said his son still had a "tender spot'' on his head and a stiff neck but was otherwise fine.
He was not sure whether he would buy a Lotto ticket because of the accident.
Tauranga Senior Sergeant Nigel Ramsden said police did not often encounter children riding on the back of vehicles and Friday's incident was unfortunate.
"We went to check it out but it was really an accident as far as we were concerned,'' Mr Ramsden said.
Federated Farmers Bay of Plenty president John Scrimgeour said children needed to be supervised at all times on rural properties.
"If a child is sitting on the back of a vehicle without someone there to supervise him, it's very risky. Without anything to hold them in it is very easy for a child to be thrown off.''
On Wednesday, Hawke's Bay 6-year-old Ashlee Petrowski suffered critical head injuries following a quad bike accident involving four adults and alcohol. On Christmas Eve, 3-year-old Te Haeata Pitiroi died after being run over in the shared driveway of his south Taupo home.
