Chelsea's profligacy, not the referee cost them.

Iniesta's goal was Barcelona's first shot on target. 

The funny thing about Chelsea's reaction to getting knocked out of the Champions League was in spite of their finger pointing, it was still their own fault. It just keeps coming back to Hiddink's decision to substitute Didier Drogba with twenty minutes to play. Drogba was causing Barcelona serious havoc all through the game and to replace him with Belletti was absolutely baffling. At that stage Barcelona were already down to 10 men and they were there for the taking. 

Defending a 1-0 lead when a Barcelona equaliser would have put Chelsea out of the competition was an extremely risky and ultimately costly strategy. By removing Drogba from the field,  it took the pressure off the Barcelona defence which seemed to liberate the rest of their team. As for Chelsea, the decision eliminated the focal point for all their attacks. They became utterly toothless upfront and the last twenty minutes became a contest between the Chelsea defence and the Barcelona forwards. 

Had Drogba been left on the field, Chelsea would be in the Champions League Final by now and if Ivory Coastian was looking for someone to blame on the night then he might have been better off asking questions of his manager. The reason I'd let the referee off the hook is because referees have a history of being terrible. They have made mistakes, presumably since football was first played competitively but players of the stature of Drogba and Ballack have been around long enough to know that by now. 

Chelsea were deservedly knocked out in the end because they couldn't put Barcelona away despite being given every opportunity and incentive to do so. There were only more controversial decisions in the Barcelona penalty area because Chelsea so completely dominated the game. The poor referee was probably so stunned by the battering being dished out to one of the aristocrats of football that he couldn't bring himself to make it any worse for them. 

Hiddink for all his genuine brilliance as a manager has made this sort of faux paus in the past. Russia tried something similar against Spain in the European Championship Semi Final last summer. Having completely dismantled the Netherlands in the Quarter Final, Russia played a much more defensive game against the Spaniards and paid the price. Hiddink's teams are at their best when they are underdogs and on the attack which is probably a reflection of his combative and aggressive nature. 

The reaction of the Chelsea players after the game was scandalous but it also distracted from their own shortcomings on the night. They lacked the killer edge and gave Barcelona 20 minutes to find a winner. Their players might not be as powerful or strong as Chelseas but they have more than enough guile and skill come up with a goal if you sit back and allow them to attack.