But rather than risk another rap from the FA, the City boss decided to keep quiet about the spot-kick, which was converted by former City striker Paul Dickov to give Blackburn a 78th-minute equaliser.
"I don't know whether it was a penalty or not but it doesn't matter now," Keegan told the official City website.
"We have lost Danny Mills now who will be suspended.
"We didn't lose and we went up one place in the table but it is another home game gone by," added the City chief.
"We have now drawn three, won two and lost two at home when we should be winning."