The Portuguese went down in the Spurs box and, as players often do when they think they've been fouled, briefly grabbed hold of the ball as he rolled on the deck. Referee Mark Clattenburg didn't give a penalty, but then he didn't signal for handball either, shaking his head and waving play on.
One of two things can be assumed:
1. That Clattenburg did not see the handball by Nani
2. That Clattenburg saw it and - with keeper Heurelho Gomes picking up the loose ball and Spurs thus back in possession - he did not think it worthy of stopping play.
Either way, Gomes really has to take much of the blame because he willingly refused to play to the whistle. Whether there was a referee error in missing the handball or not, a player can not take it upon himself to make the rules and make a referee's decision for him.
But in a way I have to point a finger at Clattenburg as he did have an opportunity to make a stand against gamesmanship by overturning the decision to allow the goal.
The assistant referee flagged immediately, one assumes having spotted Nani's handball, and Clattenburg would have been within his rights to disallow the goal after conferring.
This assumes that Clattenburg missed the original handball and was not merely playing on - but the referee still has not explained himself so we have no way of knowing!
There has been a lot of speculation in the press about Roberto Mancini allegedly losing the Manchester City dressing room, if he ever had it in the first place.
I said this before about Mancini - he has never had this many talented players before, even when he won the Italian league with Inter Milan.
Even Sir Alex Ferguson and Arsene Wenger would struggle to keep this dressing room of egos and superstars happy, but Mancini has not shown great man-management in recent weeks.
The team was winning and playing well. But suddenly, a couple of weeks back, he criticised Joe Hart and Adam Johnson for going out drinking.
Let's get this straight - the demands on players are greater than in my day and they are paid accordingly. They should not have gone out at that time.
When players do go out and make a mistake, you don't go out and criticise them to the press, you simply say it will be dealt with in-house.
You do not go outside the dressing room and if one thing does upset players it is to go outside the dressing room. Mancini hasn't done enough in English football to warrant this yet - Sir Alex or Jose Mourinho or Wenger could, but Mancini can't afford to embarrass players who he is struggling to win over.
Young boys need to have a good time but the timing is what is important. Mancini said these players should rather go with a woman than a drink. While this may have been partly in jest it was; a) irrelevant, because they may just as well have a drink with said woman, and b) the comments should not have been made to the press.
There is a drinking mentality that needs to change - and is changing, believe me - but it will only happen gradually. Also, I take offence at the accusation that it is peculiarly a British problem as there are many examples of this kind of behaviour in Italy and Spain, even if it is tolerated less.
What Mancini did by going public was to isolate his core of British players, who responded by going out drinking the following week! Now he has had to criticise them again, and it was followed by a poor performance in defeat at Wolves.
Phil Brown embarrassed his players at Manchester City and that didn't go down well: it could even be blamed for their slump in form and, ultimately, relegation.
There are few people that would take public embarrassment in their stride. Mancini has the perfect person alongside him in Bryan Kidd to deal with players and to learn about man management.
There were many occasions at Manchester United where Kidd took lads to one side and had a quiet word, with Sir Alex aware of what was going on but using his 'good cop' to keep everyone in check before it became a serious matter.
Kidd did that role at United, and Mancini should look to him for help here. He may well need it.
I was delighted to see Kevin Nolan score a hat-trick for Newcastle in the derby, particularly given what has happened to him in the past few weeks.
I don't think calls for him to play for England should be heeded though.
Kevin did well against a team that never turned up but he's not got the right kind of game for international football.
A good Premier League player? Maybe. He was a decent one at Bolton but struggled at first at Newcastle before doing well in the Championship.
Hopefully he can get back to that level of consistency he had at Bolton.
England are poor at the moment and will throw anyone in there to try and change things.
While Kevin has a great attitude, the existing central midfield options we already have means that he does not add anything in terms of quality.
And that, if anything, is what England lack at times.
- Mark Clattenburg