A missing person appeal was launched after Mr Phelan left the hospital, and his body was discovered off St Peter’s Way on August 15 .
A pre inquest review was held at Woking Coroner's Court on Wednesday (May 25), where coroner Darren Stewart said further information was needed about the search, in particular the initial 24 hours.
The court heard that questions had arisen over a reported sighting of Mr Phelan not long after he left the hospital "near the location where his body was discovered", and how that information was treated by the search team.
Referring to Mr Phelan’s initial ‘medium risk’ status, Rachel Marcus, barrister for Mr Phelan’s family, said information was needed about how that status would affect the search efforts, compared to being ‘high risk’.
Miss Marcus also appealed to Mr Stewart for the process to be treated as an "article two inquest", which is given in circumstances where the state or "its agents" have "failed to protect the deceased against a human threat or other risk".
She raised questions about what advice Mr Phelan, from Walton , would have been given by doctors and what "reasonable steps were taken to safeguard" him.
Mr Stewart said he would consider her application.
The coroner added further statements were needed from police officers involved in the search, as well as GP Sarah Styles who had a telephone consultation with Mr Phelan in the days before his disappearance, and the agency triage nurse who saw Mr Phelan when he went to A&E.
A full inquest into Mr Phelan’s death is due to be heard from September 19 to 22.