Davidson had allegedly been punched in the face and fell to the ground hitting his head, knocking the 45-year-old unconscious, police said.
Grant Coleman, 42, has been charged with assault causing death. He is the brother of Waratahs coach Darren Coleman, who had driven to the mid-north coast on Sunday to support his family.
Emergency services were called to Sportsmans Way in South West Rocks just after 11pm on Saturday.
Davidson was treated at the scene by the paramedics and taken to Kempsey Hospital where he was pronounced dead shortly after.
Police arrested Grant Coleman at his home about 30 minutes after the alleged assault. He was charged with assault causing death. He was refused bail and due to appear before Port Macquarie Bail Court on Sunday.
A crime scene was established at the location and was examined by a forensics team on Sunday morning.
