He was working on his own, strapped to the pole and plummeted about 15 metres when it fell.
The evidence focused on the installation of the pole and work processes.
Otago Southland Coroner David Crerar yesterday praised the Steel family for its perseverance.
"For 20-odd months it has worried you and others as to how those electrical burns occurred and it does you credit that you persevered.''
Pathologist Alexander Dempster told the inquest Mr Steel had multiple severe injuries as a result of the fall and those injuries were "unsurvivable'' but he also had electrical burns on his neck and arm so the cause of his death could also have been electrocution.
The line he was working on for Delta was 240v but it was near the Tallaburn 33kV line. Several electrical engineers gave evidence about the possibility of the lines touching or getting close enough to boost the current, as the pole fell over.
Mrs Steel said it was some solace that the family had more information.
"In the court case, nobody said he might have been electrocuted but now we know that might have happened and he might have died from that, before hitting the ground.''
Rebecca Steel said it was important for the family to know about her father's last few minutes.
"We had to find out exactly what happened : he deserved to have the right ending.''
Ministry of Business, Innovation and Employment health and safety leader Clive McGregor gave evidence it was an "avoidable'' incident.
The power pole had been identified as unstable and it should have been tagged or marked, and the information placed on the job card.
Coroner Crerar has reserved his finding.
After the hearing, Delta chief executive Grady Cameron said the company was co-operating fully with the inquiry and was committed to ensuring any recommendations were incorporated into its safety practices, in addition to the recommendations the company had already implemented following an independent review.