A coronial inquest into the death of Canberra man Tahadesse "Tad" Kahsai heard on Tuesday that two months after the Australian Federal Police suspended a four-day search of bushland around the hospital, students found his remains nearby in an area officers had overlooked.

Coronial investigator Matthew Callaghan told the ACT Coroner's Court that multiple issues prevented police deploying search and rescue teams sooner in 2015, and recommended changes to Australian Federal Police and Calvary Hospital procedures to stop a repeat of the incident.

Earlier, the lawyer representing Mr Kahsai's family, Brodie Buckland, said they were in the court "not seeking vengeance but vindication".

"Essentially he was a very vulnerable person allowed to slip through the cracks either through policy error or human error and the family wants to know why," he said.

First Constable Callaghan said when Calvary Hospital contacted police about Mr Kahsai's departure on December 30, 2015, Australian Federal Police asked it to submit a report, and waited until it received the document before it would dispatch officers to the matter.

A Calvary staff member's typing error meant police did not get the email, and they did not begin investigating Mr Kahsai's disappearance until another hospital staff member called the next day following up, First Constable Callaghan said.

He recommended that police, no matter how they were notified of a missing person, create a dispatch job for the case and that they are prompted to follow up the matter if they receive no further information.

The hospital had warned that Mr Kahsai was delirious, not competent and was a risk to himself when he left treatment four days following his admission on December 26, 2015 with alcohol withdrawal symptoms.

A wardsman spoke to Mr Kahsai after he exited Calvary Hospital but did not learn it was missing him until later, prompting First Constable Callaghan to recommend it colour code its patient wrist bands to indicate their risk of absconding.

Mr Kahsai's three children and a long-time friend sat in court as First Constable Callaghan explained that a police officer decided the missing person report's delay mitigated the need for a 24-hour response time, and dispatched officers to the missing man's Reid home on December 31 believing he would have returned there.

The officers working on the investigation also went on leave throughout January 2016, and during that month police did not act on the case for periods totalling at least 13 days.

First Constable Callaghan said that without a handover of a case, a "meaningful" investigation ceased.

Misinformation from a neighbour, who wrongly told police that Mr Kahsai had been home, also slowed efforts to find him.

Police searching his home also didn't find his phone in clothes inside the unit until February, and an earlier discovery may have prompted them to consider search and rescue sooner,  First Constable Callaghan told the court.

He said an officer conducting the early investigation reported he called the hospital to clarify information about Mr Kahsai and was told, contrary to its medical report, he had been "competent and capable".

The officer rated the risk to Mr Kahsai as "high" on an assessment but an acting sergeant did not confirm the rating, a decision influenced partly by the misinformation police had received from the man's neighbour and the report they said had come from a hospital staff member that he had been "capable", the court heard.

First Constable Callaghan said this decision marked a point at which Mr Kahsai's chances of being found alive were reduced, and recommended it be mandatory that any report about a missing patient be made by the treating doctor only so that information about the person remained consistent.

Had this been the case, and if police had created a dispatch job upon receiving a phone call, police would have sought advice that would have led to a quicker emergency response, increasing Mr Kahsai's chances of survival, he said.

On January 28, or 29 days after he went missing, police deployed a search and rescue team throughout a 1.23km radius of the hospital, however by this time they did not expect to find him alive and their surveys of terrain beyond this area were focused only on shelter.

Police suspended the search after four days and on April 2, 2016 two Canberra Institute of Technology students conducting environmental monitoring found Mr Kahsai's body in bushland 1.9km from the hospital and near Bruce Stadium.

A brief prepared for the court described Mr Kahsai, who moved to Canberra from Eritrea to study in the 1970s, as having "an infectious sense of life", "a broad political awareness", and "enormous potential".

He was "fun loving", charismatic, popular yet "someone to be taken seriously", however his health deteriorated as he developed a dependence on alcohol.

In the year leading to his disappearance he had drawn police attention multiple times for incidents relating to alcohol use.

Magistrate Beth Campbell said the inquest was not intended to be an "exercise in blame" but a search for "useful recommendations". The case continues and will hear from at least 17 witnesses until its expected finish on Friday.