Passing sentence, HHJ Trowler KC said: “You ran behind Mr Netto, who was posing no threat to you at all. You pushed him to his back with both your hands and swept away his legs, causing him to fall face-first onto the pavement.
“He was then left on the ground motionless, and you were seen laughing as you jumped over his body before rejoining your group.
“Within seconds of leaving Mr Netto on the ground, you can be seen shaking hands with your friend with some enthusiasm.”
Before the attack, Mr Netto had been drinking at a pub and happened to meet his killer and a large group of teenagers on his way home.
At first, his interactions were friendly. But the killer could be seen trying to pull Mr Netto’s pants down and a scuffle ensued.
The group then ran away, but the 17-year-old returned and pushed him from behind. In footage of the attack, the killer could be seen running up behind Mr Netto before shoving him with both hands to the floor while sweeping his legs from underneath him.
He then ran away when approached by police, and tried to claim Mr Netto had sexually assaulted a young woman. He told officers: “The guy touched the girl, he shouldn’t have, what the f*** are you talking about?”
Mr Netto passed away around 12 hours after the attack. A special post-mortem found he died due to a hypoxic brain injury caused by a long cardiac arrest due to the fall.
Judge Trowler described Mr Netto as intelligent, cheerful and nonviolent. He is survived by his son Stefan, 29, daughter Jennifer, 31, and 55-year-old wife Ligi.
Speaking at the Old Bailey, Ms Netto said: “The day he died, the nightmare began. He has always been there for us and then he was suddenly gone.
“He has left us and this world without getting a chance to say goodbye. The void in my heart will remain until the day I die.”
His daughter Jennifer added: “My father’s death was caused by the actions of a vile human being. We do not feel we have had any justice for this enormous loss.
“He was cheerful and loved to make people around him laugh. We miss the constant humour and light that was once in our lives.
“We are left scarred for life. We will never come to terms with what happened that night. He was attacked and killed by a sadistic criminal.”
She told The Independent: “I feel it is bittersweet. One year for manslaughter is quite lenient. But we’ve been coming to court for 11 months and feel our voice hasn’t been heard. This is the first time we’ve left the courtroom feeling a little bit of peace.”