Of all the tiresome aspects of modern football, surely none is so tiresome as the kneejerk recourse to blaming conspiracy for a team's failings. Zlatan Ibrahimovic was at it after AC Milan's comprehensive defeat to Barcelona on Tuesday - and it was comprehensive: 61% possession to 39%; 17 chances to 2 - complaining about the second penalty awarded by the referee Bjorn Kuipers.
"I'm just disgusted," the Sweden international said. "They are the best team in the world but at 1-1 and, playing with intelligence, you can do something. I understand better why [Jose] Mourinho gets upset every time he plays here - in my opinion it was not fair. We were there until the second penalty, and this we have to discuss."
This, of course, being the second penalty awarded when Alessandro Nesta grabbed a handful of Sergio Busquets shirt at a corner, hauling him back in full view of the referee. "The ball wasn't in play and he called it. It was weird, odd, it ruined the game," Ibrahimovic said. "I still don't understand what he whistled. If he calls those he should call the others. Without him the game would have been 50-50."
Was the ball in play? Well, it is true that the shirt-pulling started before the corner was taken, but it was still going on afterwards. Besides, the argument is utterly disingenuous: Nesta cheated. Don't cheat and you don't get punished. Is a lot of shirt-pulling in the penalty area unpunished? Well, yes, but then a lot of murders are unsolved: that doesn't mean you don't take action when crime and perpetrator are obvious. A lot of referees would have missed it? So praise Kuipers for being one of the few who didn't.
There are those who protested at Carles Puyol's part in the whole affair. Yes, he stepped across Nesta. Yes, he fouled him. But that foul came second. It was a direct response to Nesta seizing hold of a team-mate's shirt. Perhaps, applying the laws to their letter, he should have been booked, but still the first foul is the one that takes precedence. It's still a penalty.
Then there is the argument that Puyol had already made blocking runs at previous corners and that Nesta's grab of Busquets's shirt was a response to that. Well, first of all, blocking runs in themselves aren't illegal (although they may become so if a player is deliberately charged or impeded). And, secondly, could it not equally be the other way round: that the culture of blocking runs has sprung up precisely to combat shirt-pulling? Either way, the fact remains. Nesta cheated and was punished.
Pep Guardiola's restraint in responding to Ibrahimovic's comments was admirable. "They were fouls in the area and they were given so they were two penalties," he said. "This is what I have been taught since I was a child."
Yet that he was asked at all, that there was any sort of fuss, is baffling. This is one of those phenomena in which everybody is guilty. It suits fans, players and coaches to allege conspiracy because it means they don't have to take the blame: it wasn't that the other team was better than us; it was that we were cheated, robbed by a system stacked against us. Managers use it to pressure referees, applying psychological pressure so that when there is a tight call they give it in favour of a side they have been accused of being prejudiced against in the past.
They also use it to generate a siege mentality as a motivational tool.
At times, as when Alex Ferguson toppled the Old Firm with Aberdeen, it is based in fact: in Scotland the football culture favoured Rangers and Celtic because the football culture always favours the big teams. This is the way of things, just as cricket umpires are far more likely to give out a tail-ender than they are a top-order player. There is a perception of how things should be and, rather than challenge it, human nature makes it easier to go along with that.
At others, it simply makes no sense. Manchester United have a vast supporter-base and a history of playing attacking cavalier football; they are box office and always have been, yet Ferguson managed to get his players in the late nineties to believe there was a conspiracy against his side.
And journalists love it because it makes for easy copy. So widespread is the instinctive recourse to blaming referees, that a lot of post-match press-conferences consist of nothing but the discussion of often utterly uncontroversial decisions. You wonder where it could end.
"Lee Harvey Oswald, Lee... any thoughts on that big call going against you?"
"Well, obviously the referee's got a decision to make but for me Kennedy was looking for it. He's gone down very easily there."
But what is particularly insidious is the suggestion that the second penalty was given because referees automatically favour Barcelona as though some directive had gone out from Uefa to ensure they reach the final. It's true that the dismissal of Robin van Persie in Arsenal's last 16 tie against Barcelona last season was odd: right under the letter of the law, but utterly wrong under the spirit and in any reasonable interpretation of it. But that is one decision, one referee having a cranky moment.
To inflate that into a conspiracy is lunacy. If there were a conspiracy to favour Barcelona, would they not have been awarded at least one if not two penalties against Milan in the first leg at the San Siro? Would they not have won a penalty in the first leg of their semi-final defeat to Internazionale in 2010 when Dani Alves was clearly fouled? Would their late goal in the second leg of that tie, wrongly disallowed for a handball by Yaya Toure, not have been given? Would Nesta not have been booked for a late tackle on Cesc Fabregas early in Tuesday's game and so been sent off when he collected a second yellow for his part in the penalty?
Sometimes referees get things wrong. Sometimes decisions are borderline and a multiplicity of decisions are right. Sometimes, as in the case of the second penalty on Tuesday, referees get the decision right but some people don't like it so they sulk and invent reasons the referee was wrong. What is truly worrying is the effect that has: cry wolf and when there is true conspiracy - as the history of football tells us there has been on a number of occasions - and the genuine outrage is lost amid the expedient howls of the bad losers.
Disagree with the decision that gave Barcelona their second penalty and you'd be wrong; call it conspiracy and you risk destroying the fabric of the game.