Autopsy results were in keeping with him drowning in sea water. Langford had been last seen about four kilometres from the mouth of the river, and high tide had peaked about two hours earlier.
But the coroner said there were several possibilities why Langford drowned.
He said that Langford may have lost his footing in the river and, wearing chest-high waders and a backpack, been unable to regain it.
He may have unexpectedly stepped into a deeper part of the river - the search and rescue efforts showed that some parts of the river were one to two metres deep but others were deeper.
Coroner Kay also said Langford may have experienced a “medical event” which caused him to fall into the river.
“I had hoped to be able to reach a conclusion about why Tim drowned,” the coroner said.
“Sadly, the evidence does not allow me to say whether Tim got into difficulty in the river following a medical event, or after merely losing his footing.”
Langford, who had been widowed since 2011, had been living in Opotiki at the time of his death but had also lived in Havelock North.
More than 50 people at any one time were involved in the search for him, including police, a dive squad, a LandSar team, Hawke’s Bay Surf Lifesaving, and the Hawke’s Bay Rescue Helicopter.