Published Wednesday, 31 October 2012
At an inquest held in Belfast on Wednesday, Coroner John Leckey decided that alcohol and the cold both contributed to the 20-year-old's death.
Joby was leaving a city centre nightclub in the early hours of 26 January this year when he separated from his girlfriend and fell into the weir close to the Odyssey.
His body was found a month later, when the Murphy family brought sonar detection equipment from Co Cork to take part in the search effort.
His father, Joe Murphy, told UTV the verdict gives them closure.
"We didn't know until today did he jump, did he fall... So we are happy enough now with the verdict that said that he did actually fall over, he swam towards one of the boats and got to one of the boats, let out a yell of help and was never seen again," he said.
The bar where Joby and his girlfriend were had been running cheap drink promotions, and the inquest revealed he was almost four times the legal limit at the time of his death.
I am satisfied that he had not intended to take his own life and that he drowned due to the combined effects of alcohol and the cold weather.
Coroner John Leckey
"At the time of his death he was heavily intoxicated," the coroner said.
"Passers-by and a security guard had seen him leaning over the railings of the bridge over the River Lagan and then jumping into the water. Attempts had been made to engage him in conversation and to persuade him to move on."
Mr Murphy said he was angry that these promotions are continuing to run in nightclubs and bars across Northern Ireland.
"We know he was a happy fella but alcohol did change him, and he was at cheap alcohol nights with £1 a shot and he drunk far too much of it," he explained.
"The cheaper it is, the more people are going to buy in these nightclubs. It's not pints, it's shorts and shots and they're very, very strong. He was over four times the limit, and he was not able to save himself he had that much alcohol in his system."
After Joby's death the family set up the Joby Murphy trust fund and raised £45,000 to buy sonar equipment, with donations from members of the public and the band Snow Patrol, who Joby had seen that night.
"It's ready to help any family in need anywhere in the British Isles," explained Mr Murphy. "That's the legacy he's left behind and his name is on that sonar equipment."
© UTV News