Other than having a possible go at Oliver, I'm not sure what your point is Microscopist. The overall foul count per the BBC was 12 fouls against City and 9 against United. Can I suggest that the reason United conceded fewer fouls was because your team was so superior, my team couldn't get near enough to tackle, and when we did it was powder puff attempts most of the time to take the ball off you. Perhaps you heard Roy Keane afterwards complaining it was a derby and United got only 1 YC. That was nothing to do with Oliver being generous, he was emphasising how feeble United were.
I do agree that Ronaldo's challenge out of frustration at the end was probably of the 'orange' hue but overall I thought Oliver judged the temperature of the game very well after a more controversial performance in Europe midweek. The 2 City YC's were justified in my opinion and, like Keane, my complaint was United didn't get stuck in enough to warrant a YC. Even the daily mail gave Oliver 8/10 which was twice as high a mark as many of the United players.
The possible penalty to City wasn't dwelt upon, so whether there was enough contact for a penalty or the defender got a slight nick on the ball first, I've no idea. If I was a City fan, my only complaint wouldn't be about the referee but they didn't score as many as Liverpool 2 weeks previously. Our defending was laughable especially for the second goal, and after several fine saves, de Gea contributed to it.