Ngog went to ground in the penalty area without being touched by Birmingham midfielder Carsley.
He told ESPN: “I was absolutely nowhere near him. It’s a joke.
“I knew I didn’t touch him and I said to the referee to book me or send me off, it would have made me feel better.
“I’m sure he (Ngog) has got a family, well if I went home having done that I’d be embarrassed.
“You’re supposed to be teaching your kids an example and that is just an embarrassing case of cheating.
“But the lad’s taken a chance and got his team a point so I’m sure they’ll be patting him on the back.”
Blues boss Alex McLeish added: “This is a shame for the game.
“He conned the referee and got his team a penalty. Peter Walton is a good referee but he got that one wrong. If it hadn’t been for the penalty, I thought we’d have gone on to win it.”
The game between Birmingham and Liverpool at Anfield ended in a draw.