For 13 years, from Christchurch to London and back, former All Black Mr Karam fought long and hard to free Bain, a fight he today painted as being against "the evil" He had won tests as an All Black, big races as a horse owner, but none was as big as his win today, nor against odds that at first were set so greatly against him.
He was everywhere during the trial, organising and overseeing, passing notes, even taking his turn on the defence team's coffee run to Coffeesmiths across the road from the courthouse.
As well as emptying his bank accounts, his fight cost him personally, as friendships foundered under the weight of his obsession.
He had to defend a defamation action taken against him by a police officer, and spent 2-1/2 years of "working night and day" to prepare Bain's defence.
Campaigning for Bain has taken up nearly all of his life since he became involved, but he only ever contemplated giving up when he was being sued.
He earlier put the personal cost -- in terms of actual costs, lost earnings and lost opportunities -- at between $3 million and $5 million.
Mr Karam told NZPA two years ago he first became interested in Bain in 1996 after reading an article about supporters trying to raise money to get his case to the Privy Council.
"It struck me that they must have been genuinely convinced about what they were doing to go to such lengths, when this was just a person they had only known for a couple of years." The Bain family had been in Papua New Guinea, only moving to Dunedin in 1990, Mr Karam said.
He said he had planned to check if the supporters were genuine, then send them a couple of hundred dollars for their kitty.
"And one thing led to another after that.
"I've probably been through the most productive earning years of a businessman's life, really -- from early to mid 40s to mid to late 50s...not getting any money. The real cost is obviously millions."
He once described his crusade as "a very sapping exercise". He had believed "without any shadow of doubt" that Bain was innocent, but this was not the point.
"The point is that the evidence that we now have is vastly different from the evidence that was put before the jury that found David guilty."
There was not one defining moment when he believed Bain was innocent, but rather the evidence started to unravel, he said.
"Mainly because the police in particular were so obstructive in assisting with investigating things that didn't get investigated properly in the start."
