McIlroy (23), a painter and decorator, was a member of the triples team that failed to make the cut on the slow 13-second greens at New Delhi.
The greens were four or five seconds slower than those in New Zealand and they played erratically.
"The line to the jack was deceiving," McIlrory said. "But it was the same for other teams and you had to get used to it."
McIlroy, one of the most promising younger bowlers in New Zealand, was disappointed with the results.
"We didn't play well when it mattered," he said.
"We lost two early games and it cost us in the end."
McIlroy was happy with the Games village in Delhi.
"It was fine," he said.
"We expected worse because of the way the media portrayed it.
"All we need is a place to eat and sleep."
McIlroy did not escape Delhi belly.
"I caught it two days before we left and travelled home with it," he said.
"I had two days on the toilet but saw my doctor when I got home and he gave me some pills to get rid of it."
McIlroy won the Speight's' Invitation Singles on his first attempt in 2006 and also two years ago.
He has two caricatures of himself, painted by former Queenstown and now Canadian bowler John Parson, on the wall at the North East Valley Bowling Club.
"If I follow the sequence I could win again this weekend," he quipped. "But it will be a bit harder because the greens are different from those at Delhi. I will try to start well and take it from there."
McIlroy is a talented singles player and has won four major singles tournaments in New Zealand over the past four years - the Speight's Invitation Singles at North East Valley in 2006 and 2008 and the Stoke singles in Nelson in 2008 and 2009.
He was the singles player for New Zealand in the transtasman series in Brisbane last year and won his three games. He teamed with Gary Lawson and won two of the three pairs games as well.
McIlroy is a member of the Ngatiporou tribe and is one of the few Maori who have excelled at the top level in men's bowls.
"My parents have been my greatest supporters," he said.
"They always tell me to strive to be my best."
McIlroy first represented New Zealand when he won a silver medal in the fours at the at the Asia and Pacific championships in 2007 and has been a regular ever since.
He won the New Zealand title in 2006 and has won 14 centre titles - eight in Gisborne and three each in Nelson and Counties.
SPEIGHT'S'S INVITATION SINGLES
> First held: 1990 (20th year).
> Previous winners: Ken Walker (1990), Andrew Curtain (1991, 2003), Trevor Morris (1992), Ben King (1994), Rowan Brassey (1995, 1997, 2007), Ian Dickison (1996), Tom Ellem (1998), Mike Kernaghan (1999), Jim Scott (2000, 2001), Pail Girdler (2002), Russell Meyer (2004, 2005), Shannon McIlroy (2006, 2008), Shaun Scott (2009).
> Prize money: $20,000 (winner $6,400).
> Format: 32 players in 4 sections (top two in each section to quarterfinals).
> Dates: Section play (seven games from this afternon until Sunday ). Post-section Sunday afternoon. Final from 1pm Monday.
> Venue: North East Valley Bowling Club.
