"The players have to take some responsibility too with Michael Cheika – they should have voiced those concerns to the coach," O'Connor said.
"It was brought up quietly (with O'Connor) by a few players that the high-risk strategy (wasn't working). Somebody need to stand up.
"We had some reasonably strong personalities but we didn't have a strong enough group.
"They didn't challenge Michael and the style of footy they were asked to play. There were players in the team that weren't sold on it.
"It was one of the failings form that campaign; players who clearly weren't sold on the style of play either didn't voice their concern or were afraid of ramifications."
O'Connor was reportedly "flabbergasted" at what he saw at the private training sessions.
"I've never seen as much dropped ball from a national team. That was disturbing," he said.
"Situations where you've got (prop) Sekope Kepu trying to tip on balls in midfield like he's Mark Ella, front-rowers playing like centres when they should be hitting the ball up…you train the way you play."
And O'Connor was apparently left none-the-wiser after asking Cheika about his 'secret' game plan.
"When you look back on it: what was it?" O'Connor said.
"That new attacking style he was going to bring to the Wallabies; it was so secretive and he had to play players out of Super commitments and fly them to Brisbane and educate them. I don't know. It was almost like a scam.
"I always thought he was holding back. I always thought he had something in reserve and was being very cagey. But he didn't. It was always going to end in tears."
O'Connor said Castle, who has since been deposed, was "hell-bent on trying to rein in Michael Cheika, and that was always going to be difficult".
"He's a particular sort of person, very strong-willed. Michael (Cheika) wasn't appointed by her. It was a difficult, awkward situation."
O'Connor said Cheika wanted to fly solo as a selector, although that wasn't unusual for a coach.
Australia crashed out of the World Cup with a 16 – 40 defeat in the quarter-finals.
Cheika was angry that his power had been diluted when Castle appointed Scott Johnson above him as rugby director, as well as a selector. The extent of problems within the Aussie rugby camp were exposed by a huge argument between Cheika and Castle at the World Cup in Japan.
O'Connor is confident about Australia's future, with quality players coming through and good coaches like former All Black Brad Thorn in the ranks.
The 59-year-old O'Connor was a superb outside back who played for the Wallabies and Kangaroos. He also coached Australia's sevens team.
He has been released as a selector because of the virus related financial issues.