His wife and three remaining children had urged her not to convict him and she had also taken that into consideration.
Outside the court, Mr Long's lawyer John Fraser said a discharge without conviction on a charge of careless use of a firearm causing death was unprecedented in New Zealand.
"It was a bold and courageous [sentencing] decision, but appropriate." He said he had not been sure what the judge's decision would be.
"The outcome was always uncertain." Mr Long quietly wept throughout most of the 80-minute hearing and gave a faint smile when he heard he would not be convicted.
After he left the dock, he walked to the public gallery and gave his wife, Helen, a kiss and a long hug before hugging other supporters.
He and his wife left the courtroom hand in hand.
Seeking the discharge without conviction, Mr Fraser said the hunting expedition the father and son and two others were on had been "meticulously well planned". Samuel Long was to have gone to a place called rata tree hide and "sit tight" there for the day, while his father was to hunt alone. The other two men were to hunt together on the other side of the block.
Samuel Long left the hut at Abrahams Bay alone about 9am, 45 minutes before his father. Mr Long initially travelled in the same direction as his son, but veered off to hunt for white-tailed deer.
Mr Long saw movement and looked with his naked eye and through his rifle scope to determine whether it was a deer, Mr Fraser said.
He was unsure, so changed his position several times "painstakingly slowly" before believing he had a deer in his sights and firing.
"Circumstances conspired in that moment to convince him to take the shot ... and the result was a life sentence of grief for this man whose friends and family describe as broken."
Otago Daily Times