HE must be seething inside. Never mind the money or the stubbornness or whatever it was that stopped Alex Ferguson from signing up Carlos Tevez during the summer – this is about the failure of instinct and judgement.
Over the years, Ferguson has made many mistakes but on balance, he gets much more right than wrong and the evidence of that is in the row of trophies he has assembled at Old Trafford.
We've seen examples of stubbornness throughout his career which appeared to be at odds with his own football philosophy – good players sent packing because they said the wrong thing or had an independent mind.
Off the pitch, his battle for the ownership of Rock of Gibraltar showed how obstinate he can be and ultimately, the fight with Coolmore impacted on Manchester United.
These issues revolve around his judgement and when he looks back at his career after he eventually retires, I've a hunch that he could well see Tevez as his biggest blunder.
Certainly, the circumstances surrounding Tevez make the decision not to sign him a potentially pivotal moment in the story of where the power lies in Manchester football.
With so much money now available at Eastlands and a manager who looks like he knows what to do with it, it would be foolish of Ferguson to imagine that Manchester City are not a real threat.
Last night's result didn't prove that but the man who scored the goals which won the game is a significant piece of evidence. Manchester City could afford him, he could not.
I've said before that the biggest irritation to Ferguson will be the fact that he had a rare opportunity to view the goods before purchase as far as Tevez was concerned.
Let's pretend that Carlos Tevez arrived in England for the first time last August to play for Manchester City and had no baggage from Old Trafford.
Based on his performances so far this season, the goals he has scored and his match-winning effort last night, would Ferguson be envious of Roberto Mancini?
Would he not see an ideal partner for Wayne Rooney, who was brilliant last night but so badly needs a foil to bring the best out of him? Of course he would.
Ferguson's instincts would tell him that Tevez is a real player, one of those rare ones who can turn a match by force of will and great ability too.
Tevez is no Rooney nor a Bergkamp, an Henry or an Ian Rush, but he brings passion and energy to everything he does and has a huge thirst for work.
That's why he was such a great foil for Rooney. In my opinion, they could have formed a partnership that would have lasted a long time and given Ferguson something he's been missing since the deadly Dwight Yorke/Andy Cole double act.
That's what made last night's events so ironic. The one man who could sort out Ferguson's problems up front was banging in goals against him and worse, he had him in the palm of his hand this time last year. How he must now regret the way he favoured Dimitar Berbatov over Tevez, playing games and sowing seeds of discontent in the players' mind.
If he knew that Manchester United would have a problem meeting the price for Tevez, he should have been love bombing him instead of forcing him to sit on the bench while players with less heart and less hunger were picked ahead of him.
All any player wants is to be loved by the club he plays for and quite clearly, Tevez did not feel wanted by Ferguson. The fans were in no doubt about what they wanted.
The return leg of this Carling Cup semi-final is now a huge game for Ferguson but he won't lack confidence that he can turn the tables on Tevez and Mancini. For a start, Mancini has Shay Given to thank for filling some big holes in the Manchester City defence.
The Irishman was absolutely fantastic last night, a phrase we're now very used to where he is concerned. He spared his defenders’ blushes a number of times which, in turn, provides us with a link to tonight's second semi-final between Blackburn Rovers and Aston Villa and proves that no club is immune to the impact of bad judgement.
The Manchester City defence has never been right since Richard Dunne was shoved out the door and it's an understatement to say that this was a stupid decision.
You won't find a single commentator on the Premier League who would not nominate him as the top defender so far this season. Martin O'Neill, not known for dishing out praise easily, has been moved to mention Dunne after almost every game such has been his impact since he arrived at Villa Park and he is one of the main reasons why Villa will be favoured to beat Blackburn and advance to the final.
Irish fans will watch Steven Reid closely to see how he gets on tonight. It is very heartening indeed to note that he will get his second run in five days for Blackburn.
All Irish football fans have been following Reid's misfortunes and would like to see him rewarded for the determination he has shown. It would be fantastic if Giovanni Trapattoni was able to name him in his squad for the game against Brazil in March.