The shots could have been fired by someone hunting possums or rabbits, Mr Crowe said. It was an unusual event, he said.
"We do not often hear about these types of incidents. In this case, we are keeping an open mind as to whether it was accidental or not."
The man, a commercial cleaner, was not physically injured but understandably very shaken, Mr Crowe said.
Anyone using a firearm near a road needed to be particularly cautious about when and where it was being fired, he said.
"We would encourage anyone using a firearm in any circumstance to use it safely and wisely. If you are hunting, identify your targets before firing, and if you are in a wide, open space be mindful of how far shots can travel and in which direction."
Mr Crowe urged those responsible for Friday's incident to contact police.
Eastern District firearms officer Miriama Mataroa said it was an opportunity to reiterate to members of the public that if they had a licensed firearm to never lend it to anyone who did not have a such a licence.
"All people wanting a firearms licence must sit a test which hammers home what they need to know about safety," Ms Mataroa said.
There were seven rules around safe firearm use which people without a firearms licence may not be aware of, which increased the risk of an accident.
Anyone with information about the incident should contact Mr Crowe at HB police on 06 8310700, or information can be left anonymously on Crimestoppers 0800 555 111.
