Patrick Boothroyd, 21, died after he and Leon Grabowski were caught in a mini avalanche as they scaled the Tower Gully on Ben Nevis in December last year, an inquest heard.
Mr Grabowski told a hearing in Bradford, West Yorkshire, how the pair of experienced climbers were near the top of the gully when he tried to cut a hole through an overhanging cornice.
He said the cornice broke off, hitting him on the head and triggering an avalanche which swept them both at least 400m (1,300ft) down the mountain.
Mr Grabowski listened in the witness box as coroner Oliver Longstaff read from his statement, which said: "Since the incident I have thought about what I could have done differently and I wish we hadn't done that climb that day."
He said the pair were part of a group of eight from Cardiff University Mountaineering Club who had travelled to Fort William for a week-long climbing trip, organised by Mr Boothroyd, who was club vice-president.
Mr Grabowski, who was 28 at the time of the incident, said he and Mr Boothroyd decided to climb the relatively easy Tower Gully, which he described as grade one, in a scale of one to 10.
He said that after the fall, which included a sheer section, he was about 10 metres from his friend and could see he was badly hurt.
He described how he immediately called for mountain rescue and sat with Mr Boothroyd, who came round and was repeatedly asking him what happened.
The inquest heard how Mr Boothroyd, from Honley, Huddersfield, West Yorkshire, was winched from the mountain, but died in hospital in Fort William.
A post-mortem found that he died from multiple injuries to his chest, head and pelvis.
Mr Grabowski suffered only bruising, but was kept in hospital overnight for observations, the inquest heard.
Asked by the coroner about cutting the hole through the cornice, Mr Grabowski said: "It was the first time I'd tried to do it but I knew it was a legitimate technique."
In a statement read to the hearing on Wednesday, Mr Boothroyd's father, Nigel Boothroyd, explained how his son was a final year geology student at Cardiff University, loved outdoor pursuits and was an experienced climber who was very safety conscious.
But Nigel Boothroyd said his son had a fall earlier that year in Wales when he suffered fractured ribs and a punctured lung when he was caught by his safety rope.
He said of his son: "He crammed a lot into his life"
And added: "He was very driven. He never wanted to waste a moment of his life."
Mr Longstaff recorded a conclusion of accident.
He said: "There is nothing in the evidence that would entitle me to conclude anything other than Patrick and his friend Leon, who had undertaken this climb, were prudent and conscientious climbers."
He said: "The disaster that befell them, as far as I can make out, is not one that could have been foreseen."
The coroner said: "This was a young man doing what he loved doing, and which he had done with considerable success and great enjoyment for many, many years.
"I do not believe there was anything careless about the way the climb was undertaken. It was simply an accident of a type which this particular pastime is susceptible.
"That it should occur on this day and with this outcome is a disaster for Patrick's family. With everything said and done, this was nothing more than a tragic accident.
"He was a young man with everything to live for and everything going for him."