"He was getting the bus to the city and he was almost across the road when he turned back," she said. "He weaved through the cars and was almost back when he was hit in the bus lane."
She said her son was a non-conformist, a talented musician and comedian.
"He was an amazing son and achieved so much in his 25 years and touched so many people's lives in that short time.
"It's not how many days you live but how you fill them. We are privileged to have him for those years," she said. "It's quite fitting that he went out on the same day as he came in."
Gareth's friend and flatmate, 23-year-old Catherine Walker, described him as incredibly creative, funny and a generous person.
Gareth had played bass guitar in bands since he was 17, most recently in Star Colour, which played in various Auckland bars and in Melbourne.
He had worked as a sound engineer, as a summer camp instructor in Texas and more recently part-time in a games and collectable store in Takapuna called Vagabond.
His work will be played at a production of Shakespeare's A Midsummer Night's Dream next month. He composed all the music for the The Rose Centre Theatre production on Auckland's North Shore.
Walker said she missed the accident by minutes.
"I was driving home and I saw the police cars and the bus, but I didn't think anything of it. When I got home I texted him, wondering where he was," she said.
She got no reply - but later she received a call from Gareth's mother. "His mum said he was supposed to be joining them for dinner for his father's birthday," Walker said. "He hadn't made it. She told me he'd been hit by a bus. It was pretty shocking."
NZBus general manager Jon Calder said the driver was off work and being supported by family and colleagues.
"We offer our deepest condolences to the Lee family and are co-operating fully with the police investigation into this incident," he said.
Police spokeswoman Noreen Hegarty said inquiries were continuing and any witnesses should contact Auckland police.
