Just 24 hours after McMahon's meat export venture Venison NZ went under in 1994, he saw the advertisement for the Wellington Rugby Union's chief executive position.
He had to drop a lot of money, but McMahon saw the chance to take on rugby as being one to combine his business experience and his "passion" - rugby.
He was with the union for around two and a half years, turbulent times with the union changing its office, and its management structure, as well as pursuing a new playing home.
McMahon left with the Railways Stadium heads-of-agreement signed and the project poised to start. He will be remembered for a reorganisation of the union office, including its first computer system, his work in assisting the union's management structure change - and as chairman of the Hurricanes steering committee.
With chief executives from Taranaki, Hawke's Bay and Manawatu, McMahon put the Hurricanes on to the right management path - although McMahon say they were beaten on one point, but he doesn't regret it.
"We put a lot of work into launching the Hurricanes, and we got it right. But it's a fact that the Hurricanes were not the first name we wanted. We asked to be the Chiefs, but that name had already been grabbed by others...
"The New Zealand Rugby Football Union had given all franchises a list of possible names to choose from, but we had initially avoided the Hurricanes because we wanted to avoid any ‘wind' connotations."
Good miss, Tim.
"Within five minutes of the first game in Palmerston North the crowd was chanting, ‘Hurricanes, Hurricanes'. It made the hairs rise on the back of the neck. I thought,"hell, we're here."
And he's a constant attender at the Railsway Stadium these days, a venue he describes as "brilliant."
Go back to the start of McMahon's WRU career, in February 1994.
"The night before I started I went to a meeting of the Stadium Steering Committee with (WRU chairman David Gray), and Fran Wilde announced the Basin Reserve `option` had been canned. So the Railways `option` became the focus of the three years I was there."
"The Athletic Park `option` was never again mentioned after that night."
McMahon's two tasks when he started were to get a more business-like focus in the union office, and change the image Wellington rugby had.
"We shifted the office from Stuart Dawsons Corner to above Farmers, where the Beefeaters Arms had been. It gave us an image and a counter where people could come in and talk to us."
McMahon initiated a computer installation. The only one in the office at that stage was a New Zealand Rugby Football Union ticketing system..
"At that stage we sent all our business of to a data processing plant each month."
McMahon remembers the work of Poneke stalwart John Davies in pushing the management structure change, as well as that of chairman Gray in talking the clubs into it.
"The management structure had handicapped the union, no doubt about that. We had to put ourselves into a management structure that moved the thing forward, instead of from precipice to precipice," McMahon said.