Wolves conceded two penalties and gave Erling Haaland the freedom of the Etihad Stadium with an error-laden performance that led to a 5-1 defeat.
But O’Neil does not believe the players are at fault and will instead seek to improve his own methods in future.
“I am responsible, I don’t want anyone to think I’m saying the players cost us,” the head coach said.
“Any mistake that’s made is my responsibility because it’s come from something we’ve worked on, or not worked on.