Mr Walker's particular concern was not just a one-off broadcast of the photographs.
If they were to be loaded on to TVNZ's website, they would be "lost to him forever", she said.
Mr Walker had made his photographs available to police for crash investigation purposes.
TVNZ lawyer Jack Hodder QC said one of the purposes of the coronial regime was to extract information from past fatalities in order for them to be avoided in the future.
"It's an exercise taken in the public interest."
Photographs used as evidence in judicial hearings would not infringe on copyright and neither would reporting on that evidence, Mr Hodder said.
The coroner came to the view that the photos would assist in the reporting of the proceedings, he said.
TVNZ had narrowed the scope of the photos down to four - of the balloon taking off, touching the wire, catching fire and falling to the ground.
None of the photos showed bodies.
The organisation did not want to show pictures that would be disturbing or that breached anyone's privacy, Mr Hodder said.
Some of the families of the balloon victims had earlier expressed their support for the photos to be released as a warning to others about ballooning.
Justice Alan MacKenzie reserved his decision.
- APNZ