Bishop believed the man - who was visiting his grandchildren - was tailgating him and when they both pulled up in Beach St, they clashed.
When the 55-year-old registered nurse went to see what the defendant was shouting about, Bishop responded by punching him in the face.
The victim required a CT scan but it turned up no severe injures, the court heard.
Four days later, Bishop was working at the back of his home and yelled at his dog which was barking. A passer-by raised concerns about how the man was treating the pet.
Bishop came out to the 30-year-old woman and pushed her in the chest, causing her to fall to the ground. When she stood back up, Bishop gripped her with both his hands around her throat, walked her backwards to the road, then pushed her over again.
Members of the public then intervened, the Otago Daily Times reports.
Despite pleading guilty to the charge, Bishop later claimed the woman had been drunk and had charged at him.
Noting the defendant had previous convictions for violence in 2002 and 2013 Judge Macdonald said: ''Assaulting someone is nothing new for you ... you are no doubt strong physically - a former boxer - you'd know the potential danger of punching someone in the head.''
Defence counsel John Westgate stressed there had been no similar incidents in the past 15 months.
He said family issues plagued his client before both attacks.
The judge said he would like to order Bishop to attend anger management but Probation confirmed his risk rating did not meet the threshold.
