Basnett called for assistance, then unplugged the cord from the power box as smoke came up from Smith's body.
Meanwhile Voschezang was woken by the commotion and came outside to see what was going on. He rolled Smith's body over and found his friend's pliers embedded into him.
Emergency services were unable to revive Smith.
Police said Smith had removed the power cord from the caravan but left the other end of the cable plugged into the campground power box.
It then appeared Smith had tried to cut the power cord using a metal Leatherman multi-tool.
The tool was fused into his hand, along with a half-cut power cord.
The power authority checked the site's power source and found it was in satisfactory condition.
Energy Safety NZ senior technical officer Miles Bonfield said residual current devices, introduced in 2013, only have to be put in at new campsite installations, so the Whangaruru campsite did not have to have them, the inquest findings said.
Police were satisfied that there was no evidence to indicate foul play.
Bell recommended that RCDs be installed at all New Zealand camping and caravan parks to protect people from the risk of harmful electric shocks.