The parents of Enda Dolan have said they could request the Public Prosecution take an appeal over the sentence handed out to the driver, who while drunk and on drugs, mowed down and killed their son.
David Lee Stewart had consumed at least six pints and four Jagerbombs when he mowed down Enda Dolan in October 2014.
Traces of drugs including cocaine were also found in the father-of-three's system.
He ploughed into the 18-year-old as he was walking along Belfast's Malone Road, driving on for 800 metres with the teenager on the roof of his vehicle.
Stewart and his passenger, William Ross Casement then sped away from the scene before crashing again a short distance away.
Yesterday Stewart was handed a seven-year sentence after pleading guilty to five offences including causing death by dangerous driving, and banned from driving for five years.
He will serve just half the sentence in prison, with the remaining three-and-a-half years spent on supervised licence.
Speaking outside court on Wednesday Enda's father said the family would consider an appeal of the sentence.
It is the PPS which would have to take any appeal over sentences handed down.
Peter Dolan, speaking on Stephen Nolan's show on Thursday, said he "wouldn't rule out" the family making a request to the PPS to make that appeal.
"It was all a bit of a shock what happened yesterday and we just have to sit back and reflect and take a bit of advice and take a look at it," he said.
Casement admitted aiding and abetting dangerous driving, and aiding and abetting failing to stop at the scene.
He was given 50 hours' community service - equivalent to just two 24-hour days' work - and two years probation. He was also banned from driving for 12 months.
His father last night apologised on behalf of his son, saying the death would stay with them both for life, but would not comment on the sentence.
William Casement (57) said: "I totally apologise to that young lad's mother and father, I really do from the bottom of my heart."
Enda's father, Peter, criticised the sentences, and branded Northern Ireland's legal system a disgrace.
"I think it's a disgrace and it's an insult to ourselves," he said outside the court on Wednesday.
"There are no words to describe how we feel."
He said the family's lives have been "ruined, shattered and damaged beyond repair".
Yesterday's hearing was told how Enda's mother, Niamh, had been diagnosed with Post Traumatic Stress Disorder.
Mrs Dolan said Stewart and Casement had shown no remorse prior to a sentencing hearing last week. "It has absolutely ruined our lives - all of us," she said.
"Not just the immediate family but his girlfriend, his friends - so many people, their lives have been affected, and there's been absolutely no remorse - none whatsoever - until Friday. We've never heard anything about remorse, and that really angers us."
Judges are bound by sentencing guidelines and, as in this case, must take into account mitigating circumstances, such as early guilty pleas, co-operation with police and remorse, as well as aggravating factors, such as intent and excessive violence.
Enda, from Killyclogher, was a first year architecture student at Queen's University. He was killed on the night of his sister Dervla's 16th birthday.
The teenager, described as a talented guitarist and artist who also excelled at running, had been walking back to his student accommodation at Elms Village when he was killed.
Laganside Crown Court heard that Stewart (31), from Grays Park Avenue in Belfast, consumed at least 13 drinks.
He drank a minimum six pints and four Jagerbombs before staggering to his car, getting behind the wheel and driving along the Malone Road. Traces of drugs including cocaine were also found in his system.
Before he mounted the kerb and struck Enda, several witnesses observed Stewart's van being driven dangerously.
After hitting the student, Stewart continued to drive with him on the roof for around 800 metres.
As Enda's lifeless body lay on the road, Stewart and Casement (21), from Belvoir Drive in the city, drove away. They crashed again a short distance along the Malone Road.
After hearing how much alcohol Stewart had consumed prior to the fatal collision, Judge Gordon Kerr told him: "The amount that night would not have been out of place at a stag night."
The judge also said: "Stewart had already consumed so much alcohol it was clear he had no business driving that vehicle."
Stewart initially refused to give a blood or breath sample. When the test was eventually done, he was found to be three times over the legal limit.
He also told police he had only drunk two pints of shandy whilst watching a Northern Ireland football match.
He later pleaded guilty to dangerous driving, causing the death of Enda, failing to stop, failing to provide a specimen and failing to remain at the scene.
The court heard he was married and had three young children.
Judge Kerr told him his behaviour had been "appalling".
Casement had been drinking with Stewart prior to the crash and was a passenger in the van. He admitted aiding and abetting dangerous driving, and aiding and abetting failing to stop at the scene of an accident.
It was the Crown's case that after Enda was carried on the roof of the van, the vehicle came to a stop. As Enda lay on the road, Casement got out of the van.
It was argued that he must have known Enda was, at the least, very seriously injured as he stood close to him, but the court heard Casement then got back into the van and encouraged Stewart to leave the scene.
Stewart, dressed in jeans, a checked shirt and with a tattoo visible on his arm, showed little emotion during the sentencing hearing. Enda's parents have said his memory will live on through the Enda Dolan Foundation, which organises youth and community activities in the Killyclogher area.
What is a young man's life worth? That's not something you can ever quantify, but it has to be more than the three-and-a-half years that David Lee Stewart will serve in jail for killing 18-year-old student Enda Dolan. Off his head on an excess of drink and drugs, Stewart (31) mowed Enda down as he walked along the Malone Road in south Belfast.