Further fuel to the fire was added by a fake German journalist who came on air to discuss the gratitude Bowie felt towards Germany and its capital, Berlin, where he recorded his landmark 1977 album Heroes.
"I couldn't have done this without David's agreement so when RTE approached me, I contacted him," said Gerry Leonard.
"David was up for the gag immediately. 'Me doing Eurovision. This is supposed to be secret. How did they find out?' He really liked the idea." Callers to RTE were split on whether Bowie was going to Eurovision.
Despite co-writing two songs with Bowie on the comeback album, which has hit No 1, the 51-year-old said he needed to continue work as a session musician.
"If one of those Bowie songs I co-wrote gets picked for the new Iron Man movie, then I'd definitely see a chunk of change, but until then I'm working," he said.
Hired first as Bowie's live guitarist, the Irishman later toured the world as his musical director on his Reality Tour, which came to The Point in 2003.
"David asked me for something Irish he could say to the crowd in The Point. My brother-in-law suggested 'Tiocfaidh ar la'. We warned David how naughty this might be but he loved that, so it was the first thing he said. The crowd went mental," he said.