Leech was out hunting alone on a day trip when he was shot by one of two men in a separate hunting party.
The men quickly went to give Leech first aid at the scene. One of the men then called 111 from his cellphone.
He said the incident was a clear case of "mistaken target".
"It's definitely a mistaken target, I would suggest."
The hunters as well as the victim's families were understandably distraught at what happened.
"All the families involved, it will be a horrific time for them."
Leech's daughter Ashley said her father was an experienced hunter who was known to hunt in the Kaimai Ranges.
Leech, also known as Gordy or Cookie, was also a devoted grandfather.
She said he was "the most humble man you would ever know."
He leaves behind his wife Marianne, several children and step-children and grandchildren and will be missed by everyone who knew him.
Leech's funeral will held on Saturday at the Katikati RSA on Henry Rd at 12 noon, followed by private cremation.
The Auckland Westpac Rescue Helicopter was sent to the remote spot and a paramedic winched down to work on Leech, however he had suffered an unsurvivable injury.
Ambler said Leech's death was a timely reminder for hunters.
"The cardinal rules around firearms, primarily identifying your target, are key to safety in the bush. It's a fairly dense bit of bush, too. The whole Kaimais are particularly dense and those rules are more important in this bush."
The roar is when stags are at their most vocal, calling to attract the attention of females. They are less cautious during the roar than at other times.
Mountain Safety Council chief executive Mike Daisley urged all hunters to follow the Firearms Safety Code.
The "vast majority of firearms-related hunting incidents can be traced back to a firearms safety rule not being followed".
"It's critical to reducing incident numbers that hunters follow these rules," he said.
