A City worker who fatally punched a friend after his shoe was thrown out of a taxi window has been jailed for three years.

Alexander Thomson broke down as details of the assault, described by the judge as “arising out of trivial, friendly horseplay”, were read out in court.

Members of 23-year-old victim Thomas Hulme’s family described how their lives have been “submerged in sadness and sorrow” since the incident in central London on 26 August last year.

The judge, Anthony Bate, said the blow, struck by Thomson as he leaned forward from his seated position behind Hulme in an Uber car after the victim had been dared to throw Thomson’s shoe out of the window, was an “isolated misuse of force whilst disinhibited by drink”.

The Old Bailey heard recruitment consultant Hulme, from Leeds, initially appeared to be fine and stepped out of the car to continue the argument with Thomson, but then collapsed on the pavement.

Killer Alexander Thomson. Photograph: City of London Police

He died in hospital the following day having suffered a brain haemorrhage.

Sentencing Thomson, 33, from Clapham in south London, for manslaughter, the judge said the case differed from those “involving gratuitous unprovoked street violence”.

He said: “A talented and intelligent young man had a promising life snatched away from him in early adulthood after you lashed out at him in a moment of drunken hot temper.

“You must live with that responsibility.”

Thomson pleaded guilty at the first opportunity.

Prosecutor Timothy Cray said Thomson, who has three previous convictions for alcohol-related violence, said he drank four pints at lunchtime on 26 August before going back to work and later having up to five bottles of beer, four vodkas, three shots of Jagermeister and two small snorts of cocaine.

Hulme was also out drinking with colleagues in central London, one of whom knew Thomson well. The defendant then joined the group heading to a house party in Clapham, with Thomson sitting behind Hulme and resting his feet against the younger man’s seat.

Cray said: “There was joking chat about Tom taking one of his [Thomson’s] shoes and throwing it out of the window. It was: ‘Go on, I dare you.’ Tom chucked it out at the traffic lights. In response, Thomson leant forward and punched Tom to the head.”

The punch, through the back of the headrest, was described by fellow passengers as between a slap and a punch but was deemed to be a “relatively modest blow”. The court heard that Hulme appeared to show no immediate injury but collapsed later when the pair stepped out of the cab.

Cray said the “unexpected blow” did not leave a bruise but did cause a sub-arachnoid haemorrhage.

In a victim impact statement, Hulme’s father, Gary, said: “Life is unpredictable and life can shock. Our lives are submerged in sadness and sorrow, although we know we were fortunate and blessed for our time with Tom.

“He had dreams and plans for the future and we have no doubt he would have made those come true.”

Hulme’s younger sister, Lucy, said: “I’ve lost my big brother who I looked up to and adored. My life now has a huge void. In some ways I have lost half of me: we were two halves of a whole person for our parents.”

Defending, Lisa Wilding QC described Hulme’s death as “a result of tomfoolery” caused by “the unluckiest blow” to the victim’s head. She said Thomson had used alcohol as a coping mechanism during various periods in his life, including after the deaths of his two brothers, but said he was now committed to abstaining from drink.

“He is properly described as traumatised and tormented by the irreparable damage caused to Mr Hulme’s family. None of that seeks to excuse his actions,” Wilding said.

Members of Thomson’s family wept as he was led from the court.