An inquest was told that Brighouse man Max Ling could have been saved from a drugs overdose if his friends had called for help.
Instead, 28-year-old Mr Ling was dumped in a field at Elland, near the M62, and died, the Halifax hearing was told.
Coroner Roger Whittaker recorded a verdict of death from drug abuse on Mr Ling, of Atlas Mill Road.
His body was found by a dog walker at 8am on May 31 last year. It was in a ditch off Pinfold Lane, Upper Edge, 50 yards from the M62.
Mr Whittaker said Mr Ling's friends had neglected to call paramedics when he overdosed on heroin.
He added: "Those who were with him failed in a simple humanitarian exercise, to afford him basic medical help. This is a tragic case."
Police said Mr Ling had died elsewhere before being dumped in the ditch. A post-mortem showed he died of heroin poisoning, a drug he had previously been addicted to.
He also had some alcohol in his body.
Det Insp Richard Nuttall said police identified Mr Ling after his brother, George, reported him missing.
The inquest was told a man visiting a house in Whitwell Grove, Elland, for drugs on May 30 saw Mr Ling unconscious on the carpet. Someone said they were keeping an eye on him.
Three further potential sightings of Mr Ling occurred in Brighouse on May 30, at his parent's amusement arcade, on his bike and walking.
Det Insp Nuttall said tracing Mr Ling's movements was difficult, as witnesses' accounts were vague because of drug use.
Police officers arrested some of the occupants of the Whitwell Grove house.
But no charges were brought because of a lack of evidence.