It was a cool, clear April day when John Dunn was dispatched to a grain mill outside the town of Guyra, in the New England region of NSW. The Tamworth tow truck driver could not have imagined he was about to prompt a dispute that, two-and-a-half years later, would throw the Australian Senate into chaos and play out on the national stage.

Awaiting Dunn at the mill's gate was Rodney Culleton, a floundering farmer and businessman from the other side of the country. He had entered an arrangement with the mill's local owner, Jack Vivers, to buy grain and use the mill to make horse feed. But Culleton was experiencing financial difficulties and Dunn's Recovery Service had been ordered to repossess his leased truck.

Dunn waited, watching Culleton potter back and forth from the nearby petrol station, until the repossession agent arrived. What transpired was unlike anything Dunn, a 40-year industry veteran, had ever witnessed. "I've never struck anyone with his strange attitude, I'll say," he tells Fairfax Media. "Not everyone complies, but most people you can talk to. They know well before it happens."

Culleton, however, put up a fight. "I got down out of my truck and Culleton was at the gate to the property," Dunn recalls. "As I've had my back turned, he's jumped in my truck and grabbed the key! He refused to give the key back, the police were called [and] later on obviously charges were laid."