A taxi driver did not spot young chef Halcyon Theuri as he lay drunk in a Derbyshire road because of the car's faulty demister, an inquest concluded.
Other factors which made it difficult to see Mr Theuri before the taxi delivered a fatal head injury were his dark skin, low light and poor weather conditions.
A coroner concluded the taxi driver did not see the 21-year-old, who worked at the Peacock in Alfreton, but that he 'should have been apparent to an observant driver'.
Speaking after the inquest at Derby coroners' court yesterday, Mr Theuri's mum Faith Marriott said 'there are lessons to be learned' concerning the 'care and upkeep' of taxis.
Mrs Marriott said: "We feel there are lessons to be learned concerning the circumstances of his death, surrounding the care and upkeep of taxi vehicles and the duty of care they should have to passengers in vulnerable states.
"We can't leave people in vulnerable states and we can't leave their fate to chance."
Her husband Andi supported Mrs Marriot during the inquest and stood silently next to his wife as she read a heartfelt tribute to their 'beautiful boy'.
She said: "This was a devastating loss because we loved him dearly – and he loved us. He was such a wonderful person and he will be missed so very, very much."
Recording a narrative verdict, coroner Louise Pinder said he was hit by a motor car at 3.46am on Monday, August 31, resulting in fatal injuries.
She said 'the driver of the motor car did not see Halcyon in the carriageway' and he 'should have been apparent to an observant driver', but factors including the taxi's faulty demister contributed to the driver not seeing Mr Theuri.
Ms Pinder said there was confusion as to who was responsible for the upkeep of the taxi as the driver was not directly employed by Alfreton company Amber Taxis, which had an arrangement with him.
She said: "There are issues that I remain concerned about. It's open for debate as to who is responsible for the maintenance of that vehicle. I will be writing to Amber Taxis but it will be in a fairly informal way."
However, the coroner revealed that the taxi has now been decommissioned and the driver in question is no longer doing taxi work.
Forensic collision investigator PC Iain McGregor said the investigation and circumstances surrounding Halcyon's death were 'unique'.
He said: "Sadly we do investigate collisions involving intoxicated people who fall or stumble into the paths of cars, but the circumstances of this is that the driver may not have been aware that he had been involved in the collision.
"It has been an exceptionally thorough investigation. There has been a lot of background work. A lot of people have been spoken to, a lot of vehicles have been examined by myself and my colleagues.
"But we have to bear in mind that a young man – it transpires a very nice, very polite, hard-working young man – has lost his life on a night out."