"I sat down for a meal... and I looked across and said, 'Whoa, that's like the bloke on the telly'," the British-born Muslim said later.
The "bloke on the telly" was Osama Bin Laden, and Jack Roche - however unwittingly - had got himself mixed up with some of the world's most wanted militants.
Roche has now been convicted of involvement in an al-Qaeda plot to blow up the Israeli embassy in Canberra.
But according to analysts, he is also guilty of a stunning level of ignorance.
Giving evidence at his court hearing in Perth, Roche gave the impression he was largely unaware of the plans afoot - even though he was given explosives training and asked to undertake surveillance of the embassy.
By his own admission, Roche was easily led. But he was also "incredibly naive and stupid", according to David Wright-Neville, of the Global Terrorism Project at Monash University, Melbourne.
"He didn't know what he was getting himself into," said Dr Wright-Neville, "and when he realised, he got cold feet."
By then, it was too late. Fearing for his life, Roche said he carried out orders to investigate the embassy.
As a result of his actions, he has been sentenced to nine years in jail.
Muslim convert
Jack Roche was born as Paul George Holland in the Yorkshire town of Hull in 1953.
He moved to Sydney in 1978, where he worked as a taxi driver and factory worker.
But he never seemed entirely happy, and converted to Islam in the 1990s while trying to combat a drink problem.
Soon afterwards, Roche came into contact with twin brothers Abdulrahman and Abdulrahim Ayub - who are believed to have headed the Australian branch of Jemaah Islamiah (JI), the South East Asian militant group blamed for the Bali bombings.
"He went looking for trouble," said Dr Wright-Neville, "and he definitely found it."
According to statements to police after his arrest in November 2002, Roche became a fully-fledged member of JI in 1996.
Three years later, the Ayub brothers sent him to Malaysia to meet Hambali, who is thought to have been the regional head of JI and is now in US custody.
Roche then went to Pakistan and Afghanistan to be trained how to use explosives. He was also introduced to Osama Bin Laden, whom he described as a "very nice man".
But it seems al-Qaeda had other ideas of how they could use this Australian convert to their cause.
He was asked detailed questions about Canberra's Israeli embassy and Jewish businessman Joe Gutnick, and by the time he returned to Australia, he had promised to find out more information.
Roche claimed that it was only when he logged onto a website showing the US FBI's most wanted fugitives that he learned the identities of some of the people he had seen.
"I was shocked. I was really taken aback," he told the court. "I was thinking, 'This is too much - this is very, very deep'."
But he said he thought he would be killed if he backed away from his promise.
"You just don't walk away from these kinds of people," he said.
So in June 2000, Roche started filming outside the embassy in Canberra.
In the resulting video, Roche can be heard telling passers-by he was a tourist interested in architecture.
A security guard replied: "Is that what it is? I didn't think you were going to bomb the joint."
By July 2002, Roche had finally realised the enormity of what he was being asked to do, and went to the US consulate in Sydney.
The embassy directed him to the Australian Security Intelligence Organisation (ASIO), where "nobody seemed particularly interested in what was going on", Roche claimed.
He said he finally got a chance to sever his ties with JI in August, when cleric Abu Bakar Ba'asyir - who Roche claimed was the head of JI and is currently being questioned in Indonesia - decided to halt the plans for the embassy attack, due to infighting between the Ayub brothers and Hambali.
In the aftermath of the Bali bombings in October 2002, the Australian police began to look again at suspected militancy within its borders.
All Roche could do then was wait for the inevitable - a call from the police. It was not long in coming.
