Dr Kidd, who said he was "disgusted'' by the sentence, said he would appeal it free of charge.
Mr Kim said the Auckland lawyer had been in contact with him and was looking into the case.
Mr Kim said he was "very happy'' for the help.
Hallwright had been taking his daughter to an appointment when he and Mr Kim got into an argument in their cars. Mr Kim got out of his vehicle and banged on Hallwright's bonnet before he was hit on Mt Eden Rd.
Judge Neave criticised the media for referring to the offence as a hit-and-run, saying Hallwright was driving "away'' from the situation, which had been escalated in seriousness by Mr Kim banging on the bonnet.
"What I know of your character ... I consider it highly unlikely you would have driven at him,'' Judge Neave told Hallwright.
He said Hallwright was a contributor to society with a "spotless reputation'' and "impeccable character'' but he did not want it to be thought that he was overlooking the "very serious'' effects on Mr Kim.
''[It caused] very significant and severe injuries to Mr Kim ... though it goes without saying you never sought out to cause those injuries.''
Mr Kim has said the surgery on his legs - he would probably need six operations in total - would cost about $150,000.
