Despite what he estimated to be an 80-metre tumble, Lance made it out of the incident with no more than a few bumps, scrapes and a sore back and neck.
"I don't know what saved me, really ...
"It felt as if someone was holding me by my back and I was just floating inside the vehicle.
"It felt like the vehicle was just rolling around me. When I landed I was just sitting back in the driver's seat."
Lance had been collecting firewood from the bottom of the gully, while his mother was picking weeds which were poisonous to horses.
"Mum was actually supposed to be in my vehicle at the time," Lance said.
"I was angry and I didn't want her with me."
After the accident, he noticed the passenger side where his mother would have been sitting was "all crushed down".
Lance was taken to hospital with a sore back and neck but was soon released. Next day he was still feeling "a little bit freaky".
"Especially when I went and had a look at it yesterday night, standing up on the top where I fell from."
Lance said all he was thinking about was what would have happened if his mother was in the car with him.
He is the son of Paul Sellars, who was seriously injured in a head-on collision in 2014, when another car crossed the centre line and crashed into his courier van.