Poor Refereeing in Arsenal v Barcelona

Studies have shown that "home field advantage" is mainly due to the fact that referee decisions are biased in favor of the home team. Probably subconsciously, the ref does not want to upset the crowd and so he biases his decisions toward what will make them happy.

Arsenal v Barcelona was a pretty remarkable example of this. The poor referee decisions that went Arsenal's way included:

• Song (Arsenal) received a yellow card for a blatant (tactical) foul of Messi. He continued playing harshly, and shortly thereafter the referee was indicating that he had received his final warning. The referee's hand gestures were: one more and you're gone. Despite that warning, Song committed at least 4 more harsh fouls without being sent off. The worst of the bunch was an attempted two-footed tackle of Messi.
  
  
• Messi's goal was disallowed when he was called offside. Careful review shows he was onside, however. I can be somewhat forgiving, here, as it does look questionable when watched at full speed, but nonetheless the decision was incorrect. In the same attack, Arsenal's defense also had a handball in the penalty area that was not penalized.
  
  
• Pedro was bowled over by Koscielny in the penalty box. Some thought Pedro was looking for the foul, but you can see in the replay that, after Koscielny bumps into him and Pedro starts to tip, Koscielny puts his arm around him and pulls.
  
  
• Arshavin handled the ball in his own penalty box, denying a scoring opportunity. Perhaps the handball was accidental, but given that Arshavin headed the ball into his own hand, that isn't much of an excuse.
  

Those are four game-changing referee decisions. Most importantly, they were four decisions that, if given differently, would have resulted in a huge uproar from the crowd. Was that part of the reason why the referee made the wrong decisions? Studies suggest it was, at least subconsciously.