Police prosecutor Dougal Matheson said Bacher learned of the incident and went to the beach at Kennedy Bay to speak to the couple but saw them leaving.
Bacher then went back to his bach, got in his vehicle and drove off to find the couple who had driven about 5km and had parked on a track to the side of the road.
"He parked the vehicle at the bottom of the track and walked up to their van carrying with him a metal bar from a socket set which he swung and smashed the front windscreen of their vehicle," said Mr Matheson.
"He was yelling and abusing the complainants while doing so. He then walked down the driver's side of the van smashing each window as he progressed."
By the time Bacher got to the rear of the van Ms Graye and Mr Forest tried to drive away and attempted to pass Bacher's vehicle, but went off the track and became stuck.
The court then heard that Bacher went back to his vehicle and drove away after causing about $5000 damage to their van.
Bacher was bailed to his home address at Ohope and police will be seeking a full reparation report when he is sentenced next month.
Ms Graye yesterday told the Herald she was relieved that Bacher had entered a guilty plea and the matter would not go to trial.
Since the incident she and Mr Forest have been staying with friends in Thames and Hamilton and yesterday were at a friend's bach at Whitianga recovering.
The couple have been too afraid to go to beaches and only on Wednesday went for their first swim since the attack.
"For us it was so scary to see this guy walk down towards us and we couldn't get away. I have never seen a killing rage in a face before and I hope I never have to again," Ms Graye said.
Despite kindness extended to the pair, Ms Graye said she was unsure if they would return to New Zealand.
"I don't know how I will feel once I have left here," she said. "It would have to be a very strong invitation, I would think."