Joseph Townsley, 63, is accused of killing Frank Baxter on May 8 last year, by "ploughing" his Ford Iveco lorry through the garden of Mr Baxter's parents' house in Newmains, North Lanarkshire, striking him and his friend, Alex Minto, 31.
At the High Court in Livingston, Townsley admitted he was "angry" when he decided to go down to the house, but claimed that it had been an "accident" and he lost control of the lorry.
Mr Townsley told the jury that father-of-three Mr Baxter, 23, and Mr Minto had caused the accident by throwing objects at his lorry which had caused an "explosion" on his cab.
He told the court he had gone down asking for "peace" but conceded he was looking to arrange a fight to conclude the trouble between the warring sides of the traveller family.
In his closing speech to the jury, advocate depute, Allan Nichol, said that Mr Townsley lost control in a moment of madness.
He questioned the credibility of Mr Townsley's explanation, saying he created a version of events to the police days after, then stuck with it throughout.
Mr Townsley, of Bogside, Wishaw, has pled not guilty to a charge he murdered Mr Baxter and attempted to murder Mr Minto.
The Tarmac contractor denies a further charge that he attempted to defeat the ends of justice by fleeing the alleged murder scene and abandoning the lorry.
The trial continues.