Sergio Aguero levelled from the spot after Alvaro Arbeloa was sent off midway through the second-half.
"I know him from Italy when he refereed an Inter-Milan derby. We spent most of the game with ten and then nine and there was a penalty that also was nonexistent," Mourinho said of ref Gianluca Rocchi.
"Now this has happened and the referee is next to the goal, ten yards from the penalty, has also decided that it was there. I have to be quiet. Still pending I have a UEFA sanction so I just want to thank you for the gift for my hundred games, a very nice plate.
"If we were eliminated from this group, imagine what would happen."