The court has heard how Hallwright and another motorist - Sung Jin Kim - were waiting at the busy intersection of Symonds St and Mt Eden Rd in September 2010.
Hallwright said yesterday that Mr Kim tooted at him before Hallwright turned down Mt Eden Rd and pulled over to find a park.
He said Mr Kim followed him, kept tooting and also pulled over.
Hallwright told the court that he got out of his car, opened Mr Kim's door and asked him in a loud voice "What is your problem?"
Mr Kim then approached Hallwright's car. Hallwright said he had his daughter in the car with him and was concerned about what Mr Kim was going to do.
But the Crown said Hallwright could have sat in his car and did not need to drive off. Prosecutor Ross Burns said in his closing yesterday that Hallwright must have seen Mr Kim and must have known there was a serious risk to Mr Kim's safety when he drove off.
Mr Kim was left with two broken legs and has told the court he needed eight lots of surgery.
Judge Neave said the case came down to what risk Hallwright thought there was in driving off.
He told the jurors to put any feelings of sympathy and prejudice out of their minds for Mr Kim's injuries or the predicament that Hallwright is in.