City fought back from 2-0 down to 2-2 in a gripping Group D encounter before having a goal disallowed and being denied what they thought was a penalty in the closing moments.
Victory would have kept their hopes of reaching the knockout stages in their hands but the result all but eliminates them from the competition prematurely for a second successive year.
Mancini went onto the field to confront referee Peter Rasmussen after the final whistle and asked what he said, the explained: "I said it was a goal. I didn't see the last situation with Mario that was a penalty. I said it was a goal.
"The referee and his staff were really poor tonight."
In his post-match press conference, Mancini was also asked to clarify what he said to a cameraman who followed him onto the field.
The Italian said the word, 'finish' but said this was his way of asking him to stop filming and did not mean anything else.
Mancini said: "The camera wanted to film me after the game. He followed me on the pitch. I said, 'Finish, finish. Do not film me. I told the camera to finish, go."
There appeared to be some confusion over this during the press conference and Mancini was annoyed this might be interpreted differently.
He said: "You know other words that I said? You were on the pitch with me?"