"My power wasn't reconnected afterwards and when I inquired with Powerco I was told that I would have to contact my energy retailer and request to have it switched back on," he said.
"We were finally reconnected at around 10.30pm."
A Powerco spokesperson said the slip damaged a pole about 10am on Thursday.
"A field crew was dispatched to restore power but were unable to reconnect customers until the slip was cleared. This caused a delay in restoring power to customers, as crews needed road access to reach the damaged pole and make repairs.
"Once the slip was cleared, crews worked to restore power as quickly and safely as possible, with all customers reconnected around 10.30pm. Powerco thanks customers for their patience."
However, O'Leary said he did not observe any damage to the pole and believed it would have been a matter of reinstalling the pole fuse.
"It makes me wonder what might have happened if I'd been out of town when the power was disconnected," he said.
"If I hadn't been there to let them know I wanted it turned back on, would it have stayed off until I got back? Would I have encountered the contents of my freezer walking out to meet me?
"When you open a gate, you close it after you and I would have thought it should have been that simple."
O'Leary said he was not sure that the wet weather was entirely to blame for Thursday's slip and thought a faulty water shut-off valve might have been a contributing factor.
Whanganui District Council infrastructure general manager Mark Hughes said there had been no reports of water leaks in the area prior to the slip.
"The council had not received any reports of a leaking toby before the slip so we don't know if this might have been a factor," he said.
"We do know the toby was damaged by the slip. Given the slip started well above the toby, our best guess is that the weather was the cause."
About 50 properties on Mt View Rd were affected by an emergency water shut-off as the slip was cleared and O'Leary said the water supply was quickly reinstated.