He had not seen Brodie or his motorbike, which was parked in a blind spot, and he thought his son was still riding the bike around the yard.
Coroner Crerar said Mr Molloy felt an impact almost immediately as he began reversing.
A friend of Mr Molloy's had pulled in to the driveway at the same time, and raced to the ute.
Mr Molloy drove the ute forward to get his son out while his friend called emergency services.
Coroner Crerar said Brodie would have run towards the back of the ute as he saw his father reverse to shift his motorbike out of the way.
He suffered head injuries and was taken to Southland Hospital where he died later that day.
Coroner Crerar said it was inappropriate for him to recommend that all vehicle be retrofitted with safety aids such as reversing cameras, but he wanted to draw attention to their availability.
He drew attention to the responsibility all drivers have to ensure that the path they are driving is clear and safe.
In another finding released today, Coroner Crerar found a 20-year-old student hit by a car on a State Highway had ran in to the road to retrieve his skateboard without looking to see if any traffic was coming.
Jamie Richard Haggath died on impact when a vehicle hit him on Carrs Road, Loburn, in North Canterbury.
Mr Haggath was seen to be riding his skateboard while listening to music on headphones.
He was seen come off the skateboard, which shot out from under his feet and in to the road.
Mr Haggath ran out in to the road to retrieve the skateboard without looking to see if any vehicles were coming.
The driver of the vehicle that struck him had applied his brakes fully and had seen Mr Haggath come off the board and had manouevred to avoid him.
Coroner Crerar said no fault in the death of Mr Haggath could be attributed to the driver.
The coroner said he hoped other skateboarders would be aware of the dangers of skateboarding on a State Highway while listening to music, and being unaware of oncoming traffic.
