Scott Calder, 23, was found dead on the beach in Longniddry Bents, East Lothian, on October 14, after a night out at a beer festival with friends.
The Masters student was very drunk and became separated from his pals, and was seen staggering along a country road on October 13.
Several members of the public dialled 999 to report concerns for Scott, and others at the festival said they told nearby officers about his condition.
Police did pick him up in their car, assessed him and decided he was safe to be left alone, before dropping him at a remote bus stop without a phone or wallet.
He was found dead around a mile away the following morning.
Scott’s grieving parents, Brian and Karen Calder, have called for a Fatal Accident Inquiry into his death and have instructed a law firm to help them get justice.
Mr Calder said he had been told by Police Scotland that a ‘notable incident’ had been recorded regarding the handling of 999 calls - a phrase used when police performance is ‘likely to have a significant impact on the reputation’ of the force.
The dad described the acknowledgement there had been failings as ‘feeling like an admission of guilt’.
Mr Calder said: “Only a few days ago I was told that calls about Scott had been designated as a notable incident.
“I was told about this as a courtesy, with no other details as to what exactly this incident meant or what it involved.
“Police Scotland say they encourage their officers and staff to capture incidents where there may be an opportunity for additional training, a change in the process or improvement in their services to the public.
“To the layman this was and is an admission of guilt. I feel as though this is the first time they are possibly acknowledging something went wrong that night.
“We knew this all along but wish we hadn’t had to wait for 21 weeks for this to emerge.”
Fewer than one per cent of calls to Police Scotland result in notable incidents, according to official figures.
Police Scotland referred the circumstances of Scott’s death to the Police Investigations and Review Commissioner, who decided officers acted appropriately.
This week officers made submissions to the Crown Office, who will now consider whether any other action should be taken in relation to the tragedy.
Chief Inspector Stuart Reid, area commander for the Borders, said: “Our thoughts and sympathies remain with Scott Calder’s family.
“I remain committed to discussing the circumstances surrounding Scott’s death with his family.
“It would be inappropriate at this time to share any further information until this meeting has taken place.”
A spokesman for the Crown Office and Procurator Fiscal Service said: “The Procurator Fiscal has received a report in connection with the death of a 23-year-old man in Longniddry Bents, East Lothian on October 14, 2018.
“The investigation into the death, under the direction of Scottish Fatalities Investigation Unit, is ongoing and the family will continue to be kept updated in relation to any significant developments.”